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Background: In recent years, it has become increasingly evident that banana projects in Uganda needed to incorporate consumer preferences into the breeding pipelines to increase the acceptability of new cultivars. A trained panel used quantitative descriptive analysis (QDA) as a tool to assess the sensory characteristics of thirty-two cooking bananas (Matooke). The aim was to investigate which characteristics best-described matooke for consumer acceptability. Results: Fourteen descriptors were generated. The preferred attributes of matooke were high intensity of yellow colour, homogeneous distribution of yellow colour, good matooke aroma, highly moldable by touch, moist and smooth in the mouth. ANOVA revealed significant differences in the yellowness, homogeneity of the colour, firmness, moistness, smoothness, matooke aroma, hardness, and moldability across the genotypes (p

Background: Gari and eba, forms of cassava semolina, are mainly consumed in Nigeria and other West African countries. This study aimed to define the critical quality traits of gari and eba, to measure their heritability, to define medium and high throughput instrumental methods for use by breeders, and to link the traits with consumer preferences. The definition of a food product's profiles, including its biophysical, sensory, and textural qualities, and the identification of the characteristics that determine its acceptability, are important if new genotypes are to be adopted successfully. Results: Eighty cassava genotypes and varieties (three different sets) from the International Institute of Tropical Agriculture (IITA) research farm were used for the study. Participatory processing and consumer testing data on different types of gari and eba products were integrated to prioritize the traits preferred by processors and consumers. The color, sensory, and instrumental textural properties of these products were determined using standard analytical methods, and standard operating protocols (SOPs) developed by the RTBfoods project (Breeding Roots, Tubers, and Banana Products for End-user Preferences, https://rtbfoods.cirad.fr). There were significant (P

International audience; Coffee is deemed to be a high-risk crop in light of upcoming climate changes. Agroforestry practices have been proposed as a nature-based strategy for coffee farmers to mitigate and adapt to future climates. However, with agroforestry systems comes shade, a highly contentious factor for coffee production in terms of potential yield reduction, as well as additional management needs and interactions between shade trees and pest and disease. In this review, we summarize recent research relating to the effects of shade on (i) farmers' use and perceptions, (ii) the coffee microenvironment, (iii) pest and disease incidence, (iv) carbon assimilation and phenology of coffee plants, (v) coffee quality attributes (evaluated by coffee bean size, biochemical compounds, and cup quality tests), (vi) breeding of new Arabica coffee F1 hybrids and Robusta clones for future agroforestry systems, and (vii) coffee production under climate change. Through this work, we begin to decipher whether shaded systems are a feasible strategy to improve the coffee crop sustainability in anticipation of challenging climate conditions. Further research is proposed for developing new coffee varieties adapted to agroforestry systems (exhibiting traits suitable for climate stressors), refining extension tools by selecting locally-adapted shade trees species and developing policy and economic incentives enabling the adoption of sustainable agroforestry practices.

Sensory attributes of cassava semolina (gari and eba)., Summary The purpose of this review is to support breeders and food scientists by examining research carried out on end‐user preferences for gari and its derived dough product, eba, in Africa. The review focused on gari regarding the physical and chemical composition of raw cassava roots, methods of storage, the composition of gari with or without enrichment, and the sensory evaluation of gari and eba. The primary sensory attributes identified to describe gari are colour, taste, texture, aroma and flavour. Texture attribute of importance is crispiness for uncooked gari, and hand feel before consumption for eba. There was a significant correlation between the sensory characteristics of gari and the starch and cyanogenic potential (CNP) contents of the raw roots. Hence, the correlation of the end‐user preferences with the chemical composition of the cassava roots could be helpful to breeders in refining selection criteria and developing high‐throughput screening methods.

Gari is a common cassava precooked dried semolina in sub‐Saharan Africa. Our study investigated the role of process parameters and mash water content on gari quality during traditional roasting stage. The statistical analysis for eight quality criteria revealed that gari quality is highly influenced by the process parameters adopted by the operators. To emphasise the twin impact of roasting parameters and mash water content, different mashes with varying water content were roasted leading to different adjustments of the roasting conditions according to the operators. When the variability of the water content becomes greater, a greater variability in the final quality of the obtained garis was observed between operators (lightness, swelling capacity, starch content, texture and colour). These results suggest that technological improvements to the gari process could be achieved by appropriate management of the roasting and dewatering parameters., Role of process parameters in gari quality during handmade roasting of mashes with different water content.

Post-harvest processing (PHP) modifies the quality of the coffee and increases the value of coffee production. The choice of PHP to apply depends primarily on the available infrastructure, local climatic conditions and the desired end-value. The objective of this study was to evaluate the influence of PHP on the physico-chemical characteristics of green and roasted coffee beans and their sensory attributes. Coffee cherries from IAPAR 59 cultivar were processed as natural coffee (CN), semi-dry coffee (CD), de-pulped coffee (CP) and floating coffee (CF). Total and reducing sugars, phenolic compounds, chlorogenic acids, lipids, proteins, caffeine and water content were determined in coffee beans collected during (10thday) and at the end of each processing. The roasted beans and their sensory attributes were also analyzed. The greatest changes at the ending point of the processes were found in total and reducing sugars, phenolic compounds, chlorogenic acids and lipids contents. The PHP presented different weight loss to achieve the same visual brown color and luminosity. Beverage sensory attributes were influenced by the PHP: CN and CP coffees presented similar intensities of coffee aroma, but higher intensity of green grassy aroma, and taste were found in CF and CN coffees. Aroma and taste precursors were modified during the PHP and these were associated to husk removal of the coffee beans, suggesting an activation of the germination metabolism during the PHP. This study allowed the characterization of the effects of the different post-harvest processing on the roasted coffee beans and provides the foundations to monitor their efficiencies in the future. Made available in DSpace on 2022-01-25T14:00:42Z (GMT). No. of bitstreams: 1 Flavor-precursors-and-sensory-attributes.pdf: 573175 bytes, checksum: 368650d928db2098f3cb1c6ea8173d83 (MD5) Previous issue date: 2020

Rootstock is widely used for the cultivation of citrus fruits because it brings resistance or tolerance to diseases or environmental constrains and modulates the fruit quality. Polyploidization is a widespread improvement strategy in citrus. The objective was to evaluate the effect of rootstock and ploidy level on the composition of essential oils. Two trials were conducted, one displaying a ‘Navelina’ orange grafted on three rootstocks and a second combining two ploidy levels (di and tetraploid) of scion (‘Pineapple’ orange) and rootstock (‘Carrizo’ citrange). The composition of peel essential oil (PEO) was analyzed by gas chromatography coupled with mass spectrometry, and a panel of experts analyzed its flavor variation with a triangle test approach. The rootstock influenced the yield and composition of the orange PEO, with a low impact on flavor. Neither the rootstock nor the scion ploidy level affected the PEO yield. Only the tetraploid level of the scion significantly modified the PEO composition, reducing the oxygenated compound fraction. Sensitive significant differences were detected between the reference sample (diploid scion–diploid rootstock) and the three other combinations. These results suggest that for the profiling of an aromatic flavor, the rootstock is a key element as is the ploidy level of the scion.

Cocoa pod-opening delay and bean fermentation promote the organoleptic quality of chocolate. The present research investigated the changes in the volatile fingerprint of cocoa harvested at a traditional plantation. Cocoa beans extracted from 2-days pod-opening delay were simultaneously fermented for 5 days using container and then sun-dried to 7-8% moisture content at five different locations: Akoupé, San Pedro, Soubré, Djekanou and Daloa. The aromatic analysis were done on cocoa using the HS-SPME-GC/MS technique. Professional panelists evaluated the sensory perceptions of the chocolate. The results shows that cocoa fermented in both Daloa and Soubré regions were differentiated by 2,3-butanediol while those processed in other regions presented highest acetoin content. However, fermented cocoa from Soubré region exhibited most amount of 2,3-butanediol, diacetate A whereas 2,3,5,6-tetramethylpyrazine differentiated those from Daloa region. Sensory properties of chocolate were not linked to the aromatic compound precursors profile of beans. The fermentation performed in San Pédro region promote both the generation of more desirable aromatic compounds of cocoa and sensory attributes of the finished chocolate. The fermentation location generates a greater differentiation of the volatile fingerprint of cocoa and the sensory perceptions of the finished chocolate.

Aleppo pine seeds are a potential candidate for the production of nondairy milk due to their high protein (26%) and lipid (37%) content and their availability. For the first time, this study presents the implementation of a manufacturing scheme from seeds to final product, including pre-extraction, extraction, and post-extraction (physical and microbiological stabilization), using a 2(7-4) fractional factorial screening design. The seven factors were seed soaking time, grinding time, temperature and seed/water ratio during extraction, xanthan gum concentration, homogenization pressure, and pasteurization temperature. Beverage quality analysis consisted of measurements of chemical composition, color, stability, and rheological behavior. The results of experimental design showed that the dry matter as well as the lipid and protein contents increased significantly by increasing the ratio (grain/water) and the grinding time. On the other hand, the extraction temperature led to a better extraction of lipids but a lower extraction of proteins. Regarding stability, xanthan gum had a negative effect, while homogenization pressure and pasteurization temperature showed their effectiveness in decreasing the particle size and increasing the physical stability of the product. Practical applications : Plant-based drinks, also called plant milks, are interesting alternatives to animal milk. They have similar organoleptic properties but are more sustainable and offer very different nutritional composition depending on the plant used. As the consumers demand is constantly increasing, setting up fabrication processes from new plant sources is relevant. Aleppo pine seeds are a potential matrix for the production of vegetable beverages because they are very nutritious and available in the entire Mediterranean area. This study presents the setting up of a fabrication diagram of a plant-based beverage made from Aleppo pine seeds. Seven production parameters were tested, including pre-extraction (seed conditioning), extraction, and post-extraction (physical and microbiological stabilization), thanks to a fractional factorial 2(7-4) screening design. The best conditions enabled the production of a final beverage comparable to other commercialized plant-based beverages in terms of nutritional and organoleptic quality.

Introduction – Flash Vacuum-Expansion (FVE) is a mild physical process based on the use of heat intake and pressure differences to disintegrate plant tissue. This emerging process has high potential in food processing, as it improves the diffusivity of functional components and enzyme inhibition. Methodology – The use of different heat intakes before depressurization was evaluated on the functional and sensory characteristics of 'Manila' mango puree using chromatographic and spectrophotometric methods, as well as a sensory evaluation. Results and discussion – Higher exposure to heat resulted in a brighter puree (6.92% increase in luminosity), 4.93% increase in yellow index, 38.15% increase in phenolic content and an increase in antioxidant capacity of 68.2% with DPPH (2,2-diphenyl-1-picrylhydrazyl) and 80.7% with FRAP (Ferric Reducing Antioxidant Power) methodology, in addition to complete enzymatic inhibition of polyphenol oxidase (PPO). The loss of volatile compounds, mainly terpenes and alkenes, was observed, in addition to the formation of furanoids. Conclusion – The FVE provides a great solution to reduce the considerable loss of the 'Manila' mango produced in Mexico.

This study sought to understand user preferences of raw, boiled and steamed sweetpotato, a staple food in Uganda. A sequential methodology involving state of knowledge review, gendered food mapping, processing diagnosis and consumer testing was used in Lira and Kamwenge districts. Preferred raw sweetpotato characteristics, were large roots (≥ 3 cm diameter) with a sweet taste, smooth skin and hard texture, while mealiness, sweet taste and good sweetpotato smell were important attributes for boiled sweetpotato. Processors, mostly women, highlighted ease of peeling and sappiness of raw roots. There were gender differences in quality characteristic preferences and perceived importance. The released variety, NASPOT 8, had the highest overall liking in Kamwenge and was well‐liked in Lira. Penalty analysis of consumer data showed that sweetness and firmness were key drivers of overall liking. The results will support breeding programmes in meeting specific end‐user product profiles, selection criteria and uptake of new varieties., Summary This study sought to understand user preferences of raw, boiled and steamed sweetpotato, a staple food in Uganda. A sequential methodology involving state of knowledge review, gendered food mapping, processing diagnosis and consumer testing was used in Lira and Kamwenge districts. Preferred raw sweetpotato characteristics were large roots (≥ 3 cm diameter) with a sweet taste, smooth skin and hard texture, while mealiness, sweet taste and good sweetpotato smell were important attributes for boiled sweetpotato. Processors, mostly women, highlighted ease of peeling and sappiness of raw roots. There were gender differences in quality characteristic preferences and perceived importance. The released variety, NASPOT 8, had the highest overall liking in Kamwenge and was well liked in Lira. Penalty analysis of consumer data showed that sweetness and firmness were key drivers of overall liking. The results will support breeding programmes in meeting specific end‐user product profiles, selection criteria and uptake of new varieties.

International audience; Vacuum frying is an alternative technology to obtain fruit snacks with higher sensory and nutritional quality compared to traditional fried snacks. Vacuum frying of a carotenoid-rich fruit (red-fleshed papaya) was performed at 25 kPa, using soybean oil at 100, 120, and 140 ◦C from 0 to 14 min. The study aimed to monitor and model physicochemical changes that chips undergo during vacuum frying, which are related to their sensory and nutritional attributes. Moisture content, aw, oil uptake, sugar content, browning index (BI) and carotenoid contents were monitored. Water loss and oil uptake followed first-order kinetics while the decrease in aw followed a logistic trend. Glucose and fructose followed the same degradation pattern while BI and sucrose content increased as a function of frying time and oil temperature. β-cryptoxanthin (BCX) loss followed second-order kinetics and retention was 60 and 40% after 14 min at 120 and 140 ◦C, respectively. Contents of lycopene and β-carotene were increased suggesting an improvement in availability of these compounds to extraction. Optimal vacuum frying conditions for processing papaya fruit comprise a combination of temperatures (107–120 ◦C) and frying times (9–14 min) to produce quality papaya chips with aw ranging from 0.1 to 0.3, low color degradation and BCX loss ≤30%.

This study compared the use of pork backfat (PF) and fat-tailed sheep tail and backfat (SF) on the physicochemical, fatty acids and sensory attributes of warthog cabanossi. There were no differences between weight loss during drying, moisture content, pH, water activity, salt content and lipid oxidation between the cabanossi types. However, protein and ash contents were higher in PF cabanossi whilst fat content was higher in SF cabanossi. The PF cabanossi had higher polyunsaturated fatty acids (especially n-6), lower monounsaturated fatty acids whilst the saturated fatty acid content was similar between the two cabanossi products. The n-3:n-6 ratio was more beneficial in the SF cabanossi. The descriptive sensory analysis showed two distinct products where PF cabanossi scored higher for most attributes. Although SF cabanossi scored less for these attributes, this cabanossi had unique and acceptable sensory attributes. This study concluded that fat-tailed sheep tail and backfat could be used to produce a unique cabanossi product of acceptable quality.

This study revealed that higher proportions of women than men showed preference for most attributes of cassava flour quality., Summary Cassava breeding programmes in Uganda do not currently select materials based on flour making quality, explaining in part the low adoption rates of many released varieties. In this study, we describe end user trait preferences, processing qualities and physicochemical properties of cassava flour. We found that higher proportion of women than men showed preference for most attributes of cassava flour quality evaluated in this study. Preference for colour was 66% and 52% among women and men, respectively, while that for stickiness of Kwon was 26% (women) and 15% (men). Ease of peeling and stickiness of Kwon were key processing traits. Heap fermented flour had higher pasting temperatures, but lower viscosities than sun‐dried flour, and had lower amylose content compared to fresh root starch. The results demonstrate the importance of gender sensitive participatory evaluation of breeding materials, in tandem with physicochemical evaluation during selection of best possible candidate breeding lines.

Despite the importance of fermentation for cocoa quality, process parameters are not controlled under spontaneous conditions at farms. This study evaluates the influence of spontaneous fermentation and processing under laboratory-controlled conditions using the acidic reagents acetic and lactic acids on the cocoa quality of two cultivars, FEAR 5 and CCN 51, at the sensory and metabolomic levels. Under spontaneous conditions, cocoa differs in flavour quality. While FEAR 5 produces chocolate with good global quality, chocolate made with CCN 51 does not have outstanding quality attributes. Transformation under controlled conditions with acidic reagents increases the perception of fine aromatic notes such as fruity, nutty and floral attributes in chocolates made from both cultivars of cocoa. Metabolomic profiles allowed grouping of cocoa samples as a function of postharvest treatment. Twenty-five differential metabolites were identified during the postharvest processes, and these metabolites may be related to the expression of fine sensory attributes; however, more research is needed.

High quality characteristics of cassava roots, gari and eba (coloured boxes indicate high quality characteristics for each product), Summary User’s preferences of cassava and cassava products along the value chain are supported by specific root quality characteristics that can be linked to root traits. Therefore, providing an evidence base of user preferred characteristics along the value chain can help in the functional choice of cassava varieties. In this respect, the present paper presents the results from focus group discussions and individual interviews on user preferred quality characteristics of raw cassava roots and the derived product, gari, – one of the major cassava products in Sub‐Saharan Africa – in major production and consumption areas of Cameroon and Nigeria. Choice of cassava varieties for farming is mainly determined by the multiple end uses of the roots, their agricultural yield and the processing determinants of roots that support their major high‐quality characteristics: size, density, low water content, maturity, colour and safety. Processing of cassava roots into gari goes through different technological variants leading to a gari whose high‐quality characteristics are dryness, colour, shiny/attractive appearance, uniform granules and taste. Eba, the major consumption form of gari in Cameroon and Nigeria, is mainly characterised by its textural properties: smoothness, firmness, stickiness, elasticity and mouldability. Recommendations are made, suggesting that breeding will have to start evaluating cassava clones for brightness/shininess, as well as textural properties such as mouldability and elasticity of cassava food products, for the purpose of supporting decision‐making by breeders and the development of high‐throughput selection methods of cassava varieties. Women are identified as important beneficiaries of such initiatives giving their disadvantaged position and their prominent role in cassava processing and marketing of gari.

Dark chocolate samples were previously classified into four sensory categories. The classification was modelled based on volatile compounds analyzed by direct introduction mass spectrometry of the chocolates&rsquo, headspace. The purpose of the study was to identify the most discriminant odor-active compounds that should characterize the four sensory categories. To address the problem, a gas chromatography-olfactometry (GC-O) study was conducted by 12 assessors using a comparative detection frequency analysis (cDFA) approach on 12 exemplary samples. A nasal impact frequency (NIF) difference threshold combined with a statistical approach (Khi&sup2, test on k proportions) revealed 38 discriminative key odorants able to differentiate the samples and to characterize the sensory categories. A heatmap emphasized the 19 most discriminant key odorants, among which heterocyclic molecules (furanones, pyranones, lactones, one pyrrole, and one pyrazine) played a prominent role with secondary alcohols, acids, and esters. The initial sensory classes were retrieved using the discriminant key volatiles in a correspondence analysis (CA) and a hierarchical cluster analysis (HCA). Among the 38 discriminant key odorants, although previously identified in cocoa products, 21 were formally described for the first time as key aroma compounds of dark chocolate. Moreover, 13 key odorants were described for the first time in a cocoa product.

International audience; The present study aims at developing an analytical methodology which allows correlating sensory poles of chocolate to their chemical characteristics and, eventually, to those of the cocoa beans used for its preparation. Trained panelists investigated several samples of chocolate, and they divided them into four sensorial poles (characterized by 36 different descriptors) attributable to chocolate flavor. The same samples were analyzed by six different techniques: Proton Transfer Reaction-Time of Flight-Mass Spectrometry (PTR-ToF-MS), Solid Phase Micro Extraction-Gas Chromatography-Mass Spectroscopy (SPME-GC-MS), High-Performance Liquid Chromatography (HPLC) (for the quantification of eight organic acids), Ultra High Performance Liquid Chromatography coupled to triple-quadrupole Mass Spectrometry (UHPLC-QqQ-MS) for polyphenol quantification, 3D front face fluorescence Spectroscopy and Near Infrared Spectroscopy (NIRS). A multi-block classification approach (Sequential and Orthogonalized-Partial Least Squares – SO-PLS) has been used, in order to exploit the chemical information to predict the sensorial poles of samples. Among thirty-one test samples, only two were misclassified.

Current climatic upheavals reduce water availability which impacts the growth and fruit quality of plants. In citrus crops, scion/rootstock combinations are used to ensure high fruit production and quality and a stress tolerance/resistance. Our objective was to assess the effect on the clementine scion (C) under natural mild water deficit of (i) polyploid rootstocks by comparing the allotetraploid FlhorAG1 (C/4xFLs, trifoliate orange + Willowleaf mandarin) with its diploid parents, trifoliate orange (C/2xTOs), and Willowleaf mandarin (C/2xWLs), and with a diploid genotype used as reference (Carrizo citrange, C/2xCCs), (ii) rootstock propagation methods by comparing trifoliate orange seedling (C/2xTOs) with cutting (C/2xTOc). A mild water deficit observed under orchard conditions during the summer period (July&ndash, August) induced a significant change in yield (except in C/2xTOs), fruit size, and quality. C/2xCCs, C/2xTOs, and C/2xWLs appeared less affected by water deficit as indicated by their lower reduction of predawn leaf water potential (&Psi, pd), relative water content (RWC), transpiration (E), and photosynthetic parameters (Pnet and gs). Their greater redox balance was probably due to their better antioxidant efficiency. Seedling rootstocks lead to a better adaptation of clementine scions to water deficit than cutting or allotetraploid rootstock. Improving the tolerance to water deficit requires taking into consideration the rootstock genotype, propagation method, and ploidy level.

Introduction – Piper borbonense from Reunion Island is an overlooked wild pepper that remains unutilized today. The purpose of this multidisciplinary work was to study its anatomy, morphology and biochemical composition with a view to its possible commercial development. Materials and methods – We determined its biochemical composition using, notably, gas and liquid chromatography plus spectroscopic methods. Results and discussion – This pepper differs from Piper nigrum through the pedicel, which forms an integral part of the peppercorn. It can be distinguished from other tailed peppers, such as Piper cubeba and wild peppers from Madagascar, through its ovoid shape. Its compounds of interest, essential oil and piperine, are mostly present in the perisperm. Starch (41% db) is its main constituent. Piper borbonense has low pungency (piperine content: 0.2% db) and high aroma potential (essential oil content: 9.8% db), distinguishing it from Piper nigrum and bringing it closer to the tailed peppers, such as Piper cubeba and the wild peppers of Madagascar. Its aroma composition, very rich in monoterpenes, notably limonene (27%), can be considered as that of a good quality pepper. Conclusion – The typicity of Piper borbonense affords an interesting potential for domestication and valorization.

Chocolate is a widely consumed product worldwide due to its exquisite flavor, which comes from the unique and fascinating cocoa flavor. This flavor depends on little controllable variables such as the genotype and the agroecological niche, and on the other side, on postharvest operations: (1) cocoa transformation from seeds to beans that comprises cocoa seeds preconditioning, fermentation, and drying, and (2) the production of chocolate from the bean in which roasting is highlighted. Postharvest transformation operations are critically important because during these, cocoa flavor is formed, allowing the differentiation of two categories: bulk and specialty cocoa. In this sense, this article presents an overview of cocoa postharvest operations, the variables and phenomena that influence and control the physical and biochemical transformation from seeds to cocoa beans, and their relation to the formation of chocolate flavor. Moreover, research perspectives in terms of control and management of postharvest practices in order to obtain cocoa with differentiated and specialty characteristics "from bean to bar" are discussed.

The need to increase sustainability and add value to traditional foods claiming health benefits led to the introduction of key improvements in the production of hibiscus beverages in Senegal. The physicochemical and sensory properties of three resulting products (an under-vacuum concentrate, a dilute-to-taste syrup and a ready-to-drink infusion) were assessed, vis-à-vis those of conventionally manufactured beverages, and their impact on local consumer preference determined (n = 146). New beverages had more intense, redder colour and higher monomeric anthocyanin content, total phenolic content and antioxidant capacity. Moreover, their colour evaluations by trained panellists were mainly linked to colour density and anthocyanin/polyphenol content, while flavour assessments were associated to titratable acidity and sugar-to-acid ratio. Consumer evaluations, in turn, were driven by the beverages’ red colour intensity, aroma strength and balance between sweetness and acidity. This explained why they overwhelmingly preferred the under-vacuum concentrate, regardless of their age, gender or frequency of hibiscus beverage consumption.

White Kenley is a traditional stiff dumpling produced from fermented dehulled maize grains in Ghana. The physico-chemical modifications which occur during combination of various steeping (12, 30 and 48 h) and fermentation (0 h, 12 h and 24 h) times were assessed to study the impact of these unit operations on the quality of white kenkey . Water uptake by soaked grains and the release of metabolites were followed during grains steeping and particle size distribution after milling was determined. Steeping time exceeding 24 h was required to produce a fine wet milled flour while water uptake was completed after 8–10 h. This was parallel to hydrolysis of proteins and/or hemicelluloses which occurred after 16 h. Changes in acidity and glucose content were determined in the grain after steeping and in the dough after fermentation. The texture of the kenkey was determined using a texture analyzer. Increases in acidity were higher during dough fermentation than in steeping. Stickiness of the white kenkey decreased consistently with steeping time. Principal Component Analysis showed that a combination of long steeping and short fermentation times gives white kenkey with low stickiness (and high fineness), low acidic taste and low fermented odour.

Various chemical compounds in green coffee beans are precursors of coffee beverage sensory attributes. The hypothesis was that those chemical compounds would vary with microclimate over the vertical plant profile of coffee plants. The plants of the cultivar IAPAR 59 were grown in two high plant densities (6000 and 10,000 plants ha−1) under rectangular and square planting patterns. Coffee beans were collected from three canopy strata. Chemical compounds and chlorogenic acid isomer (CGA) contents were determined by near infrared spectroscopy and ultra-performance liquid chromatography, respectively. The free-choice profile technique was employed to estimate the sensory attributes of coffee beverage. Brightness, transparency appearance, typical coffee color and aroma, tastes as sweet, acid, astringent and bitter, and full-bodied texture were attributes detected by panelists. Plants cultivated under lower plant density had lower leaf area index indicating lower self-shading than under higher plant density. Coffee beans originated from the inferior stratum of higher density had the lowest concentrations of 5-caffeoylquinic acid (5-CQA), while the inverse situation occurred in their upper strata. Strata of lower planting density were associated to high levels of all CGA isomers. The coffees cultivated under higher density showed high lipids and CGA isomers contents. Under lower density, beans had low concentration of sucrose, proteins, and caffeine and high of CGA isomer contents. The beverage sensory attributes depended on the concentration of proteins, lipids, and sucrose in combination to CQA isomers in beans, varying over the vertical profile and planting designs of coffee plants.

The potential use of ultrasound measurements, combined with other physical measurements, has been investigated. The good relationship between soluble solids content (SSC) and ultrasonic wave velocity reported in the literature being confirmed by our study, our main goal was to evaluate the added value of ultrasound measurements around 25 MHz for the determination of biochemical compounds responsible of organoleptic quality of mangoes. Among the main sugar constituents of mango juice, only sucrose content prediction was improved by combining SSC and ultrasonic waves velocity using a PLS model ( R 2 = 0.81, RMSECV = 12.3, bias = 0.10, RPD = 2.3) when compared to the linear model with SSC only ( R 2 = 0.75, SEP = 14.05, bias = 0.08). The same conclusion was obtained for titratable acidity PLS model using whole fruit hardness, SSC and ultrasonic wave velocity ( R 2 = 0.82, RMSECV = 1.84, bias = 0.02, RPD = 2.4) compared to the linear model with fruit hardness only ( R 2 = 0.78, SEP = 2.07, bias = 0.02). However, the added value of ultrasound measurements was not always found to be significant ( P = 0.05) when a Wilcoxon statistical tests was conducted on the residuals of the linear and PLS models for both sucrose and titratable acidity.

Acceptability criteria in dessert banana were investigated to enable sensory qualities to be taken into account earlier in the assessment of new banana hybrids in a selection scheme. Twelve banana cultivars were characterized by sensory profiling and physical-chemical analyses at a defined eating stage. The 'right' levels of sourness, sweetness, firmness, mealiness, and banana aroma were evaluated by 214 consumers on the 'Just-About-Right' scale. Optimal acceptance of a banana means at the most 20% of consumers judged the banana to be e.g. 'too …' or 'not … enough'. The ideal banana received scores ranging between 6.1 and 6.7 for sweetness, between 2.8 and 3.3 for sourness, above 6.3 for banana aroma, between 3.7 and 4.7 for firmness and between 1.0 and 1.4 for mealiness on a discrete 0–9 scale, by titratable acidity of 5.5 meq 100 g−1, or a pH of 4.9, and a pulp puncture force between 1.9 and 2.4 N. Acceptability thresholds were calculated when a maximum of 33% of consumers judged bananas to be e.g. 'too …' or 'not … enough'. Screening new hybrids revealed the advantage of using an acceptability threshold of 33% of unsatisfied consumers as the first step, since after a hybrid has passed the acceptability threshold, crop management can be directed towards being as close as possible to the characteristics of the ideal banana. (Resume d'auteur)

Introduction. The high intra-specific variation in safou traits and the perishable nature of the fruit hampers commercialization. Knowledge of the parameters that determine the acceptability of safou products and the shelf life of fresh fruits is critical for marketing and useful as a first step toward cultivar development. Materials and methods. Safou fruits of different pulp colors, skin colors and stages of ripening were collected from clones. Physicochemical and organoleptic analyses were performed on fresh and processed safou pulp, respectively, to elucidate parameters that could be used to determine the acceptability of boiled and dried safou pulp, and the shelf life of fresh fruits. Results and discussions. Our study demonstrated that the pH and color of raw pulp could be used to determine the acceptability of boiled and dried safou. Consumers preferred products which were not acidic (sour), with a nice aroma. There was a negative correlation between the pH of raw pulp and the acceptability of boiled and dried safou pulp. Likewise, there was a positive correlation between the color of raw pulp and the acceptability of boiled and dried safou pulp. These parameters were used to predict the taste of finished products. Polygalacturonase activity was higher in fully ripe and unripe fruits than in semi-ripe fruits. Polygalacturonase activity had a strong positive correlation with percentage loss of fully ripe fruit during storage and, as such, can also be used to predict the postharvest loss of safou. Conclusion. The pH and color of raw (uncooked) pulp of safou can be used to determine the taste and acceptability of boiled and dried pulp. Likewise, the activity of polygalacturonase in raw pulp can be used to predict its postharvest shelf life. (Resume d'auteur)

International audience; Age of plant and environmental conditions during growing may affect texture (friability) and taste of boiled cassava roots. We investigated the quality of boiled roots of seven cultivars harvested at 10, 12 and 14 months in three different seasons. Sensory taste (sweet or bitter) of boiled cassava root could not be correlated with sugar content and/or cyanide potential, which both interfere with taste perception; hence, bitterness is not a good indicator of the poisonous character of cassava roots. Improved cultivars generally showed lower friability scores, independently of plant age (10-14 months) or season. Rainfall before harvest directly lowers dry matter and mealiness of boiled roots. Cultivar and rainfall effects are discussed in relation to pectins (higher content for improved cultivars) that are suspected to be the major biochemical cause of vegetable mealiness.

This paper describes the multidimensional features of the texture of cooked rice (in particular the visual aspect and mechanical attributes) determined by sensorial analysis and links these attributes with a wide range of physicochemical characteristics of raw grain (in particular certain cell wall components). Textural classes of cooked rice did not fit classical grain ranking, which is primarily based on shape. For the classification of cultivars, it would be preferable to use chemical characteristics of raw kernels such as amylose content and Tgel (for prediction of firmness), but also protein (adhesiveness and stickiness) and arabinoxylan contents (deformation), which determine the textural properties of cooked rice. Leached amylose has been measured, and the particular role of soluble amylose on the surface behaviour (stickiness and adhesiveness) of the cooked grain is discussed.

Lactic acid bacteria (LAB) and propionic acid bacteria (PAB) are widely used in the manufacture of cheeses and other fermented dairy products. Bacterial species used as starters are mainly chosen according to their intrinsic properties: the milk acidifying capacity for LAB starters and the aromatizing properties of PAB, for example. Beyond the general characteristics of a bacterial species, many key phenotypic traits determining their interest for dairy applications depend on the strain within a given species. Through some examples, this review illustrates how the choice of a bacterial strain with specific technological characteristics, within a given species of LAB or PAB, can determine the final properties in the end product. This concerns the technological properties of cheeses, such as flavour, texture, and opening formation, and their functional properties, such as inhibition of undesirable microorganisms and health properties. When known, the genetic determinants of the diversity are presented. This review emphasizes the importance of preserving and exploring microbial resources at the intraspecific level, as an unending source of diversity for innovation in food fermentation.

Because of the high temperatures applied in classical refining processes, many quantitative and qualitative changes occur in the chemical compositions of oils. This causes refined olive oil to lose many of its organoleptic and nutritional properties. Research has been carried out to ascertain the influence of a soft purification process, based on oil conditioning, to form micronic aggregates which were subsequently removed by a microfiltration operation. The quasi total acidity and the resulting soaps were removed in a single microfiltration step. The deacidified and filtered oils showed similar peroxide values and the variation of the specific extinction around 270 nm ([delta]K) was slightly improved. The process lowered the monoglyceride contents up to 78% while the diglyceride contents were just slightly decreased. The various sterol components were also lowered (in the range 36-50%) upon treatment. Phenolics were the most affected components; reductions reached 93%. The partitioning of such components between the bulk triglyceridic medium and the aggregate phase are considered with regard to their properties. Despite the low operating temperature, the sensory evaluation of the deacidified and filtered oils still showed poor organoleptic characteristics. (Resume d'auteur)

International audience; Introduction. Zizyphus mauritiana Lam. est un arbre fruitier sauvage très commun en Afrique sahélienne. Ses fruits, les jujubes, sont traditionnellement exploités par cueillette dans les peuplements naturels et représentent une source de revenu importante pour de nombreuses familles rurales. Ils sont consommés frais ou secs. Au Sénégal, un programme d'introduction de variétés de jujubiers améliorés d'origine indienne est en cours depuis plusieurs années. L'objectif des travaux présentés a été de comparer la première variété introduite (Gola) avec deux lots de jujubes locaux. Matériel et méthodes. La comparaison entre différentes origines a porté sur les caractéristiques biométriques des fruits et sur les teneurs de la portion comestible en divers composés organiques et en éléments minéraux. L'étude a été complétée par une enquête gustative auprès de consommateurs. Résultats et discussion. La portion comestible des fruits frais de Gola est environ vingt fois plus importante (en poids et volume) que celle des jujubes locaux. La pulpe des Gola est plus riche en eau et moins concentrée en éléments organiques (sucres, protéines) et minéraux (calcium, magnésium). Cependant, après séchage, les teneurs ne sont plus significativement différentes, si ce n'est celles des protéines et de quelques éléments minéraux dont la richesse chez Gola diminue très nettement pendant le séchage. Les fruits de Gola séchés, très parfumés, ont été les plus appréciés par la population sénégalaise. Conclusion. Quelle que soit leur origine, les jujubes sont riches en sucres, en vitamines C, en calcium et en fer. Ces fruits représentent un apport nutritionnel important pour les populations des régions arides. La variété Gola répond bien au goût du consommateur sénégalais. Sa diffusion en zone sahélienne peut donc être envisagée sous réserve d'avoir levé au préalable les contraintes techniques liées à la production des plants et d'avoir vérifié la rentabilité économique de cette nouvelle culture

International audience; Amongst all kinds of coffee brews, “specialty coffee” is conspicuous in particular by a unique flavour. “Bourbon Pointu” coffee, Coffea arabica var. laurina, born from a spontaneous mutation of the Bourbon variety in Reunion Island, is a “specialty coffee”. This study aims at identifying potent odorants of “Bourbon Pointu” coffee brew according to its three trade classifications “Grand cru”, “Sublime” and “Authentique”. Solid phase extraction (SPE) permits to extract the volatiles. After their identification by gas chromatography–mass spectrometry (GC/MS), the potent odorants are determined by their odour activity value (OAV). The determination of their \OAV\ allowed one to differentiate coffee brews from the three trade classifications. Aromatic composition of “Bourbon Pointu” coffee is characterised by a predominance of aldehydes with high \OAV\ (e.g. (E,E)-nona-2,4-dienal: 13,600) for coffee brews belonging to “Grand cru” classification, of 2-phenylacetaldehyde (270) for coffee brews of “Sublime” classification and of a group of pyrazine compounds (e.g. 2-methyl-5-propylpyrazine: 16,750) for coffee brews of “Authentique” classification.

Chemical composition of Hibiscus drinks (Koor and Vimto varieties, commercial and traditional, infusions and syrups) (n = 8) was related to sensory evaluation and acceptance. Significant correlations between chemical composition and sensory perception of drinks were found (i.e. anthocyanin content and Hibiscus taste) (p < 0.05). Consumers (n = 160) evaluated drink acceptability on a 9-point verbal hedonic scale. Three classes of behaviour were identified: (a) those who preferred syrup (43% of consumers); (b) those who preferred infusion (36%); and (c) those who preferred all of the samples (21%). Acceptability of 'syrup likers' was positively correlated to sweet taste, reducing sugar content and inversely correlated to acidic taste and titratable acidity (p < 0.10). Acceptability of 'infusion likers' was positively correlated to the taste of Hibiscus drink and anthocyanin content. The study showed that the distinctions between the acceptability groups are very clear with respect to the chemical composition and rating of sensory attributes.

Numerous studies have been carried out to investigate energy density and consistency of gruels for infants in developing countries. However, starch-rich gruels have a complex rheological behavior and their consistency is difficult to characterize. Many published gruel viscosity data are available, but the lack of standardized viscosity measurement procedures makes comparisons and interpretations difficult. The influences of viscometer type and viscosity measurement conditions on gruels prepared with simple or multicomponent flours were assessed in this study. The results showed a drastic decrease in apparent viscosity when the shear rate increased. Other factors like shear time and gruel temperature also had a marked influence on apparent viscosity. For two types of gruel (maize or multicomponent flour) prepared at different concentrations, correspondences between a short qualitative description of the consistency and apparent viscosity values obtained with several viscometers in different measurement conditions are given. Finally, recommendations are put forward on techniques to obtain valid data on gruel consistency, adapted to each type of study (laboratory, field or large-scale surveys).

In free living conditions, 24 breastfed infants, aged 6 to 10 months, were given successively five experimental gruels to study the effect of energy density (ED) and sweetness (sweet taste) on energy intakes (EI). Four gruels (G0, G1, G9 and G20) were prepared with experimental flours which were composed of the same local ingredients and which contained different levels of sucrose. The fifth gruel (GC) was prepared with an industrial flour. G0 has an average ED of 45 kcal/100g (189kJ/100g) and the other gruels an average ED of 100kcal/100g (461kJ/100g). Although the sugar contents of the flours were 1% for G1, 9% for G0 and G9 and 20% for G20, because of flour composition and gruel dry matter content, the gruel G1 had the same sweetness as G0, G20 the same sweetness as GC and G9 a sweetness between that of G1 and G20. The results show that the amounts of G0 consumed were significantly higher than those of high ED gruels (7.84 for G0 vs 6.12, 5.63, 4.46, 4.72g/kgbody weight/meal, respectively for G20, G9, G1 and GC, P is less than 0.05). However, EI from high ED gruels were significantly (P is less than 0.001) higher than those from G0 (6.65, 6.10, 4.86, 4.83kcal/kg/meal, respectively for G20, G9, G1 and GC vs 3.46 for G0). Energy intakes from G9 and G20 gruels were not significantly different but were significantly higher than those from GC and G1 (P is less than 0.001). So, consumption of sweet gruels with high ED and composed of local ingredients increased, at least by 76%, the EI from gruels in comparison with those from low ED gruels, but the amounts consumed by the infants remained too low to cover more than 15% of their daily total energy needs. (Résumé d'auteur)

International audience; To be able to account for sensory qualities earlier in the assessment of a new banana hybrid in a selection scheme, predicting the sensory perception of banana texture and taste by instrumental parameters was investigated. Thirteen cultivated banana and four new triploid hybrids were characterized by sensory profiling, and rheological and chemical analyses. Multilinear regressions were used to calibrate predictions using 13 cultivated bananas, and the quality of predictions was validated using four hybrids. The sensory characteristics sourness and sweetness were predicted by titratable acidity (R-2 = 0.68) and pH (R-2 = 0.66). Malate and citrate were the main contributors to sweetness and sourness. Astringency was predicted by total tannins (R-2 = 0.55). Rheological parameters from texture profile analyses (stress at fracture, fracturability) were more suitable than pulp puncture force to predict the sensory texture properties firmness (R-2 = 0.47) and melting (R-2 = 0.60). These textural properties were predicted by titratable acidity and dry matter content (R-2 = 0.62). Predictions of mealiness, adhesiveness, and heterogeneity were not efficient. Differences of 3.6-3.7 meq 100 g(-1) FW in titratable acidity or of 0.30 g 100 g(-1) FW in malate or. citrate were required to ensure a detectable difference in sourness or sweetness (p = 0.9). Pulp puncture force needed to differ by a minimum of 0.9 N before a difference in firmness could be perceived by the panelists. In conclusion, while models to predict sourness and sweetness can now be used for high throughput phenotyping, we recommend additiqnal tests for other sensory attributes. (C) 2013 Elsevier B.V. All rights reserved.

The electrodialysis (ED) process was investigated to reduce the acidity of four tropical fruit juices, passion fruit, castilla mulberry, najanrilla and araza. In this part of the study, the results of physico-chemical and sensory analyses of juices treated were collected and compared to fresh juices. Low differences (

Shubat and Koumiss are traditional fermented products widely consumed in Kazakhstan and Central Asia. Microflora of those fermented products is composed of bacteria and yeasts, which could have deep impacts on beverages quality. Although, the known presence of yeast in such fermented foods, few studies on yeast microflora of Shubat and Koumiss were available. The aim of the study was to identify the main indigenous yeasts in these traditional beverages and additionally, the differences between these 2 types of fermented products. Five samples of fresh and fermented camel and mare's milk from tank were collected in 5 different farms, located in South of Kazakhstan. Farms were selected because of their importance of production of fermented milk at the regional level and the reputation of these products among the consumers. Yeast biodiversity in Shubat and Koumiss was studied using denaturing gradient gel electrophoresis (DGGE). Target DNA bands were identified according to the reference species ladder, constructed in this study. Co-migrating bands present in the DGGE profiles were resolved by species-specific PCR. Galactomyces geotrichum, Kluyveromyces marxianus, Kazachstania unispora, Saccharomyces cerevisiae, Dekkera anomala, Dekkera bruxellensis yeast were identified. Some yeasts were not identified by used primers. In all samples of Shubat and Koumiss the dominant yeast species were Kazakhstania unispora, Kluyveromyces marxianu. Other species were not present in all samples.

Standardized techniques are still needed to characterize the consistency of gruels for infants in developing countries. The aim of this study was to evaluate the interest of the use of the Bostwick consistometer. Bostwick flow was measured on gruels prepared with different flours, at low or high energy density (i.e. without or with amylase). The range of Bostwick flow, from 0 to 240 mm/30 sec, adequately described a wide range of gruel consistencies from completely liquid to almost solid. However, the temperature of the gruel must be carefully controlled during measurements as Bostwick flow is highly temperature dependent, especially in the case of gruels with high energy density. The relationship between Bostwick flow and apparent viscosity proved to depend on the type of gruel: at an apparent viscosity of 1 Pa.sec, gruels prepared from maize, rice, millet or multicomponent flours had different Bostwick flow values of, respectively, 20, 35, 75 and 55 mm/30 sec. Sensory analysis was then performed with a panel of mothers of infants and young children in Ouagadougou (Burkina Faso). Gruels of similar apparent viscosity and different Bostwick flow distances or of inversely similar Bostwick flow distances and different apparent viscosities were prepared by adding carob seed flour, and differentiation and ranking tests were then carried out. Both types of test revealed that mothers differentiated similar gruels having different Bostwick flow distances more easily than gruels having different apparent viscosities. It can thus be concluded that Bostwick flow, which is an empirical multi-criteria parameter, conveys the sensory perception of gruel consistency better than apparent viscosity.

Volatile compounds from cured vanilla beans were extracted using organic solvents. Sensory analysis showed that the aromatic extract obtained with a pentane/ether (1/1 v/v) solvent mixture provided the extract most representative of vanilla bean flavour. Sixty-five volatiles were identified in a pentane/ether extract by GC-MS analysis. Aromatic acids, aliphatic acids and phenolic compounds were the major volatiles. By GC-O analysis of the pentane/ether extract, 26 odour-active compounds were detected. The compounds guaiacol, 4-methylguaiacol, acetovanillone and vanillyl alcohol, found at much lower concentrations in vanilla beans than vanillin, proved to be as intense as vanillin.

The physicochemical properties of twenty promising new improved cassava cultivars (13 sweet and 7 bitter), harvested at maturity in Benin, were assessed. In parallel, instrumental measurements and sensorial tests were performed to assess boiled cassava quality. These properties and physicochemical properties were tentatively correlated. The colour score of boiled cassava tuber was closely correlated with ΔE measured on fresh pulp, while mealiness (or friability) could be assessed by resistance to penetration, measured on cooked tuber slices. Mealiness could also be predicted from starch functional properties (such as apparent viscosity after pasting), cyanide potential and the water content of fresh tubers. The cassava tubers had a narrow amylose content range (18.2%–22.6% starch basis). In addition, bitter cultivars appeared to be quite homogeneous with, in particular, high sugar and protein contents but low fibre contents. They also had original starch functional properties, with high solubility and low paste viscosity.

Quercetin content in onion ( Allium cepa L.), represented mainly by 3,4′- O -quercetin diglucoside (3,4′-Qdg) and 4′- O -quercetin glucoside (4′-Qmg), was examined in five cultivars before and after three cooking treatments (sauteing, baking, and boiling). Baking and sauteing produced a 7–25% gain in quercetin concentration, while boiling produced an 18% decrease in quercetin concentration. Ratios of 3,4′-Qdg to 4′-Qmg in tissues ranged from 1:1.3 and 1:1.7, and combined the two conjugates represented 89–90% of total flavonol content in treatment and raw control means indicating heat stability of the flavonols. Changes in flavonol concentrations as a result of cooking method were consistent across all five cultivars.

Some physicochemical and cooking characteristics corresponding to different varieties and commercial samples of rice were analysed. Some mechanical properties determined by both, the viscoelastograf and the Instrom Universal Food Testing Machine were also analysed. Gelatinization time (Gt), gelatinization endotherm and amylose content were determined. The results showed that there was a very good correlation between gelatinization temperature and Gt, while no noticeable correlation among others phsycochemical characteristics was observed. Regarding the mechanical properties, both methods permited to show significant differences among most of the samples. However, when the samples order obtained with hardness (Instrom) values was compared with that corresponding to firmness (Viscoelastograf) values, some discrepancies were observed. This could be attributable to the number of grains and the cooking time used in each method. There was good linear correlation between hardness and amylose content. On the contrary, none of the viscoelastograf parameters are correlated well with amylose. An interesting point was that the slope of the regression line obtained between firmness and cooking time could be utilised as a measure of cooking resistance of each sample and was related to the rate of water absorption.Oito variedades e quatro amostras comerciais de arroz de boa qualidade foram analisadas com relação a algumas características físico-químicas e de cozimento. Algumas propriedades mecânicas foram avaliadas utilizando-se tanto o viscoamilógrafo como o equipamento Instron (Instron Universal Testing Machine), tais como, o tempo de gelatinização (Gt), a endoterma de gelatinização e o conteúdo de amilose. Os resultados mostraram que existe uma boa correlação entre a temperatura de gelatinização e Gt, contudo não foi observada correlação relevante entre outras características físico-químicas. Em relação às propriedades mecânicas, ambos os métodos permitiram mostrar significantes diferenças entre algumas amostras. Existe uma boa correlação linear entre dureza e conteúdo de amilose, por outro lado, nenhum dos parâmetros viscoelastográficos apresentaram boa correlação com a amilose. Um ponto interessante é que a inclinação da reta de correlação linear obtida entre firmeza e tempo de cozimento pode ser utilizada como uma medida da resistência ao cozimento de cada amostra e relacionada à taxa de absorção de água.

Submitted by Guilherme Lemeszenski (guilherme@nead.unesp.br) on 2013-08-22T18:53:01Z No. of bitstreams: 1 S0101-20612003000300006.pdf: 603393 bytes, checksum: 9977171d2bf9d36cab8776cb6d96ca17 (MD5) Made available in DSpace on 2013-08-22T18:53:01Z (GMT). No. of bitstreams: 1 S0101-20612003000300006.pdf: 603393 bytes, checksum: 9977171d2bf9d36cab8776cb6d96ca17 (MD5) Previous issue date: 2003-12-01 Made available in DSpace on 2013-09-30T19:44:31Z (GMT). No. of bitstreams: 2 S0101-20612003000300006.pdf: 603393 bytes, checksum: 9977171d2bf9d36cab8776cb6d96ca17 (MD5) S0101-20612003000300006.pdf.txt: 35337 bytes, checksum: d8526b4364b604c690ccf224ebda66b3 (MD5) Previous issue date: 2003-12-01 Submitted by Vitor Silverio Rodrigues (vitorsrodrigues@reitoria.unesp.br) on 2014-05-20T15:11:41Z No. of bitstreams: 2 S0101-20612003000300006.pdf: 603393 bytes, checksum: 9977171d2bf9d36cab8776cb6d96ca17 (MD5) S0101-20612003000300006.pdf.txt: 35337 bytes, checksum: d8526b4364b604c690ccf224ebda66b3 (MD5) Made available in DSpace on 2014-05-20T15:11:41Z (GMT). No. of bitstreams: 2 S0101-20612003000300006.pdf: 603393 bytes, checksum: 9977171d2bf9d36cab8776cb6d96ca17 (MD5) S0101-20612003000300006.pdf.txt: 35337 bytes, checksum: d8526b4364b604c690ccf224ebda66b3 (MD5) Previous issue date: 2003-12-01 O objetivo deste trabalho foi introduzir a técnica de microfiltração tangencial (MFT) na produção de suco de laranja. O suco microfiltrado (SMFT) foi comparado química e sensorialmente com um suco pasteurizado (testemunha). Utilizou-se um piloto de MFT munido de quatro membranas (0,1, 0,2, 0,8 e 1,4mm) cerâmicas monotubulares dispostas em série, cada uma delas com superfície de 0,005m². Suco de laranja comercial flash pasteurizado foi usado como produto inicial. O trabalho experimental foi dividido em três fases: a) caracterização do piloto de MFT; b) otimização das condições operacionais; c) produção do SMFT. Na fase de otimização, a membrana de 0,8mm apresentou os melhores fluxos de permeado, seguidas pelas de 1,4, 0,1 e 0,2mm. Para garantir a esterilidade do permeado, a membrana de 0,1mm foi escolhida para a terceira fase do trabalho. Na produção do SMFT, o suco de laranja foi peneirado para separar uma parte de sua polpa, sendo em seguida microfiltrado. Depois, a polpa foi misturada ao retentato e a mistura pasteurizada. O SMFT foi obtido adicionando a mistura pasteurizada ao permeado. O SMFT apresentou teor de sólidos solúveis (°Brix), polpa, pH e acidez titulável semelhante ao suco inicial pasteurizado (testemunha); embora, tenha perdido maior quantidade (28%) de vitamina C. de acordo com os provadores do painel, o suco testemunha apresentou melhores características sensoriais em relação ao SMFT, por apresentar maior intensidade de odor e sabor frutoso. The aim of this study was to introduce the tangential microfiltration (TMF) technique on the production of orange juice (TMFJ), and compare it with pasteurised juice (control) as regards chemical composition and sensorial characteristics. We used a TMF pilot equipped with four monotubular ceramic membranes (0.1, 0.2, 0.8 and 1.4mm) arranged in series with a filtering area of 0.005 m² each. Commercial flash-pasteurised orange juice was used as the initial product. Experiments were divided into three parts: a) the characterisation of the TMF pilot; b) optimisation of operational conditions; c) production of the TMFJ. In the second part, membrane with 0.8-mm pores presented best flux followed by those with 1.4-, 0.1-, and 0.2-mm pores. However, to guarantee permeate sterility, we chose the membrane with 0.1-mm pores for TMFJ production. Initially, the orange juice was sieved in order to separate part of the pulp, being subsequently submitted to TMF. A mixture of retentate and pulp was made, and was subsequently pasteurised. We obtained the TMFJ by adding the permeate to the mixture. TMFJ presented soluble solids content (°Brix), pulp, pH, and titrable acidity similar to the initial pasteurised juice (control). Nevertheless, 28% of vitamin C was lost during the TMFJ production. According to the juice taster panel, the control juice presented best sensorial characteristics (greater aroma intensity and fruity flavour) when compared with the TMJF. UNESP IFCA CIRAD FLHOR Université de Montpellier II UNESP IFCA

The high acidity of passion fruit limits its addition in food preparation. In order to easy the uses of this juice to formulate high aroma and flavour products, its citric acid content must be decreased. Various methods such as calcium salts precipitation, ion-exchange resins and electrodialysis with homopolar and bipolar membranes were investigated to increase the pH of a clarified passion fruit juice from 2.9 to 4.0. Each deacidification process was compared in terms of characteristics of deacidified juices such as concentration of inorganic and organic ions, colour and flavour. The deacidification by precipitation using CaCO3 was not recommended because of CO2 release. The ion-exchange process gave a poor quality juice in terms of organoleptic characteristics. Electrodialysis with homopolar membranes induced an increase in the sodium concentration. Precipitation with Ca(OH)2 and electrodialysis with bipolar membrane were the most suitable processes in terms of sensorial properties of juices treated. The physico-chemical analyses showed an increase in the calcium concentration with the use of Ca(OH)2 that could cause some precipitation problems in the final product. Inorganic anions were eliminated together with citrate by using electrodialysis and resins. Nevertheless, electrodialysis with bipolar membranes presented great advantages: it was a continuous process without reagent addition moreover allowing the production of a valuable solution of citric acid.