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The effect of different drying methods on sugar content and amino acid content, color and non-enzymatic browning of Chilean papaya (Vasconcellea pubescens) slices was investigated. The obtained fruit extracts were tested in cell viability assays on human endothelial ECV-304 cells. Drying techniques included freeze-, vacuum-, solar-, convective- and infrared-drying. Consistently, infrared-dried papaya had a lower sugar content and a higher non-enzymatic browning intensity than papaya dehydrated by the other methods. All dried samples were lighter in color with a lower yellow intensity compared to fresh papaya. The amino acid lysine was the most abundant in the infrared-dried sample. On the other side, the methods that employed vacuum, increased their cellular viability. Based on these results, operational parameters during drying processes should be considered to preserve, on one hand, product quality attributes, while, on the other hand, increasing cell viability.

The aim of this study was to evaluate the antioxidant, antidiabetic, anti-inflammatory and antimicrobial activities of three edible seaweed extracts from Chilean coasts: Pyropia orbicularis, Ulva spp, and Durvillaea antarctica. Seaweed extracts in methanol and 70% acetone were performed to evaluate antioxidant and antidiabetic activities, whereas 60% methanol was used to measure anti-inflammatory and antimicrobial activities. Acetone extracts from D. antarctica had the highest total phenolic content and consequently exhibited the strongest antioxidant activity, while methanol extract of this seaweed presented the highest α-glucosidase inhibition (IC50= 0.004 mg mL-1). In the tests against E. coli and Penicillium sp., the extracts obtained from Ulva spp. were the most effective and exhibited the maximum anti-inflammatory effect against phorbol 12-myristate 13-acetate irritant agent (61.8% inhibition) in mice. Results indicated that all evaluated Chilean seaweed extracts are promising candidates for application in functional foods and in the pharmaceutical industry.

Nowadays berries are globally recognized to be among the healthiest foods because they contain diverse and abundant bioactive compounds. Among these are phenolic acids, flavonoids, and anthocyanins, which are known to have beneficial health effects. South America, particularly southern Chile, is covered by a diversity of insufficiently studied and underexploited native berry species. In this review we summarize all the available literature on the phenolic composition, antioxidant activity, bioaccessibility, and biological activity of five native South American berries: calafate, maqui, murta, arrayán, and chequén. The potential of these native berries for promoting human health and as source of bioactive substances is remarkable. Bioactive compounds, mainly anthocyanins, and in less abundance flavonoids and phenolic acids, show strong antioxidant effects. Some of these constituents are bioaccessible and bioavailable, and exert anticancer, antimicrobial, and anti-inflammatory activities as well as inhibitory effects against enzymes involved in metabolic syndromes. Given the potential of native South American berries to promote health, more work is still needed to understand fully the potential beneficial effects of the consumption of these berries on human health. © 2020 Society of Chemical Industry.

Physalis peruviana L. fruits are rich in bioactive compounds with health benefits. Processing of physalis into pulp with further dehydration has been proposed as a method to increase shelf life and preserve bioactive compounds. Here, the effect of three drying methods on the physico-chemical properties, color, antioxidant capacity, tocopherol and fatty acids content of physalis pulp thin layers were evaluated. The radical scavenging activity showed higher antioxidant activity at high temperatures rather than at low temperatures. Both, DPPH and ORAC assay showed a high antioxidant capacity of the physalis pulp. Chromatic parameters as well as Chroma and Hue angle were affected by drying temperature, which contributed to the discoloring of physalis pulp during this process. Based on these results, both convective drying and infrared drying at 80 °C were proved to be viable drying options for physalis pulp.

The red seaweed Pyropia orbicularis was dried using four different drying methods (freeze-, vacuum-, solar-, and convective-drying) to evaluate the effect of the drying method on physicochemical pa...

BACKGROUND Consumption of bell peppers is recommended because of their bioactive compound content and their positive effects on health. Growth-promoting rhizobacteria are popular because of their ability to promote plant growth by improving the fixation of nutrients or by inducing a systemic response. Green bell pepper (Capsicum annum) roots were inoculated with an autochthonous strain of Bacillus amyloliquefaciens, at different stages of development: T1, inoculation in the seedbed before transplant; T2, inoculation at and after transplant; T3, inoculation in the seedbed, at and after transplant. Bell pepper plants without inoculation were considered as control. Physicochemical composition and antioxidant activity of the fruits were measured to select the best treatment. RESULTS T1 increased crude proteins, fat, Ca, Fe, vitamin C, total phenolic content, antioxidant capacity by DPPH and by ORAC. On the other hand, T1 decreased reducing sugars, K and Cu content. No significant differences for total carbohydrates, ash and photosynthetic pigments were found. CONCLUSION Inoculated green bell peppers have enhanced its functional value and could be considered as an important source of bioactive compounds with elevated antioxidant activity. © 2019 Society of Chemical Industry.

Chilean papaya slices were dried using different technologies to evaluate the effect of the different technologies on drying kinetics, bioactive compounds and biological activities. Five techniques were used: freeze drying (FD), vacuum drying (VD), solar drying (SD), convective drying (CD) and infrared drying (IRD). Fresh and dried samples were evaluated in terms of proximate composition, phenolic profiles, total phenolic and flavonoid contents, β-carotene, vitamin C, and antioxidant and α-glucosidase activities. CD-papaya showed lower processing time, requiring 270 min to reach the dynamic equilibrium condition, while SD-papaya required 870 min. The five drying technologies were found to have variable effects on proximate composition. VD-samples showed the lowest loss of individual phenolic compounds, total phenolic content and vitamin C while IRD- and CD-samples showed lower total flavonoids (42%) and β-carotene (32%) loss after processing, respectively. With respect to biological activities, all samples possessed enzymatic activity in a dose-dependent manner (0–2.0 mg ml−1), being IRD-sample the most effective in inhibiting α-glucosidase (IC50 = 13 mg ml−1). Also, the highest antioxidant capacity measured by DPPH and ORAC was obtained for the papaya samples dried using a vacuum drier.

The influence of diverse hot-air drying temperature on bioactive compounds, nutritional components, and physical aspects of apricot (Prunus armeniaca L. var. Tilton) fruits from 40°C to 80°C was evaluated. Firstly, drying kinetics was modeled by Diffusion model and Weibull equation, this last provided a good fit to the experimental data. The effect of drying conditions on the color and microstructure showed noticeable modifications due to an increase of air-drying temperature. Besides, a reduction of antioxidant activity, total phenolic and flavonoid contents with an increase of drying temperature were observed. As to vitamin C and β-carotene were much more affected by the long drying times (>1000 min) than high temperatures (>60°C). Sucrose, fructose, and glucose were identified in all apricot samples, being sucrose the predominant sugar. Thus, results from the present study indicate that the hot-air drying technology continues to be applicable for obtaining a dried functional product of good quality.

To evaluate the effect of drying methods on Stevia rebaudiana Bertoni quality, the content of bioactive compounds, antioxidant capacity, antimicrobial and anti-inflammatory activity of Stevia leaves dehydrated by seven different methods was compared. Polyphenols and antioxidant capacity increased in all dried samples where Freeze (FD) and shade drying (SH) resulted in the highest and infrared drying (IR) in the lowest values. All Stevia leaf extracts presented antimicrobial activity towards Listeria innocua although IR and convective drying (CD) inhibition was longer (48 h). Except from IR, all extracts reduced inflammation in AA treated mice, where vacuum dried (VD) and microwave dried (MW) were the strongest. MW, sun dried (SD) and SH stevia were the most effective against phorbol 12-myristate 13-acetate (TPA)-induced inflammation. This work provides evidence on how drying processes affect the content and activity of Stevia bioactive compounds. Selection of a specific drying method for Stevia leaves can now be chosen based on the intended application, such as preparation of functional foods enriched in bioactive compounds or antioxidant capacity (FD and SH leaf extracts), or as natural extracts with high antimicrobial (IR and CD leaf extracts) and anti-inflammatory activity (MW leaf extracts). Fil: Lemus Mondaca, Roberto. Universidad de Santiago de Chile. Facultad de Ciencias; Chile Fil: Vega Gálvez, Antonio. Universidad de La Serena; Chile Fil: Rojas, Pilar. Universidad de La Serena; Chile Fil: Stucken, Karina. Universidad de La Serena; Chile Fil: Delporte, Carla. Universidad de Chile; Chile Fil: Valenzuela Barra, Gabriela. Universidad de Chile; Chile Fil: Jagus, Rosa Juana. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Houssay. Instituto de Tecnologías y Ciencias de la Ingeniería "Hilario Fernández Long". Universidad de Buenos Aires. Facultad de Ingeniería. Instituto de Tecnologías y Ciencias de la Ingeniería "Hilario Fernández Long"; Argentina Fil: Agüero, Maria Victoria. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Houssay. Instituto de Tecnologías y Ciencias de la Ingeniería "Hilario Fernández Long". Universidad de Buenos Aires. Facultad de Ingeniería. Instituto de Tecnologías y Ciencias de la Ingeniería "Hilario Fernández Long"; Argentina Fil: Pasten, Alexis. Universidad de La Serena; Chile

Chilean papaya is grown in Central Chile and is considered to be an important source of fiber, sugars, and antioxidants. The effect of different vacuum drying temperatures (40, 50, 60, 70, and 80 °C) on the composition of papaya pulp was evaluated. The inhibitory effect of papaya extracts on α-glucosidase activity, as a regulator of blood sugar, was also evaluated. Drying reduced water activity of the pulp to less than 0.6, thereby, assuring the product stability, while maintaining simple sugars, vitamin C, and total flavonoids. Total phenolic content and antioxidant capacity by DPPH assay increased with respect to the fresh pulp by 1.5 and 2.6 times, respectively. The inhibitory effect of papaya extracts on α-glucosidase was evaluated by determining the IC50 for each sample and the acarbose equivalents. The results indicate the suitability of the dried extract of Chilean papaya as a regulator of glucose metabolism in Type II diabetes patients.

Physalis peruviana L. fruits are rich in bioactive compounds with health benefits. Processing of physalis into pulp with further dehydration has been proposed as a method to increase shelf life and preserve bioactive compounds. Here, the effect of three drying methods on the physico-chemical properties, color, antioxidant capacity, tocopherol and fatty acids content of physalis pulp thin layers were evaluated. The radical scavenging activity showed higher antioxidant activity at high temperatures rather than at low temperatures. Both, DPPH and ORAC assay showed a high antioxidant capacity of the physalis pulp. Chromatic parameters as well as Chroma and Hue angle were affected by drying temperature, which contributed to the discoloring of physalis pulp during this process. Based on these results, both convective drying and infrared drying at 80 °C were proved to be viable drying options for physalis pulp.

The aim of this study is to determine the effects of different drying methods, including freeze drying (FD), convective drying, sun drying, infrared drying and vacuum drying (VD), on the chemical composition and microstructure of maqui berries as well as their anti-inflammatory and antidiabetic activities. Results showed that all dried samples have high unsaturated fatty acids contents (up to 83%) and high total dietary fiber contents (above 50%). Also, one hundred grams of dried berries provide between 11 and 21% of the recommended daily intake of α-tocopherol. Moreover, all dried maqui extracts reduced topical inflammation in treated mice. The highest anti-inflammatory effect against phorbol 12-myristate 13-acetate was found for VD and FD samples. Also, all dried maqui extracts showed antidiabetic activity by inhibiting α-glucosidase activity. The highest α-glucosidase inhibition activity was found for FD samples. The different biological activities of the dried maqui berries were related to differences in the extractability of metabolites due to microstructural changes during drying. The results indicated the potential use of dried maqui as a food ingredient with high unsaturated fatty acids, dietary fiber and α-tocopherol or as a natural extract with therapeutic agents.

14 pages, 5 tables, 2 figures, The effects of vacuum, solar, convective, infrared, and freeze drying (VD, SD, CD, IRD, FD) on Durvillaea antarctica were evaluated in terms of nutritional composition, color, bioactive components, and antioxidant and antidiabetic activities. Nutritional composition of the dried seaweeds scarcely varied, while a tendency to lose the reddish tone occurred. CD-seaweed had highest phytochemical and vitamin contents, while FD-samples showed best retention of pigments. Both samples also exhibited the strongest antioxidant and antidiabetic activities. The highest essential amino acids and polyunsaturated fatty acids contents were found in IRD- and SD-samples, respectively. In general, FD and CD were proved to be viable drying options for D. antarctica, The authors gratefully acknowledge financial support received from the Comisión Nacional de Investigación Científica y Tecnológica, CONICYT-Chile, FONDECYT Project N° 1160597.

The effects of different drying temperatures between 40 and 80 °C on bioactive constituents and antioxidant activity of edible sub Antarctic brown seaweed, Durvillaea antarctica were studied. Dietary fibre, amino acids profile, pigments (chlorophyll and carotenoids), vitamin E, total phenolics and total flavonoids as well as antioxidant activity were determined, beside a measurement of the chromatic coordinates. The brown seaweed D. antarctica had a high content of dietary fibre and was rich in essential amino acids and drying between 40 and 80 °C did not influence significantly dietary fibre content nor the level of essential amino acids that remained around 44%. However, a significant degradation of the chlorophyll pigments was observed with the lowest level of the initial chlorophyll content occurring at 60 °C (59%). Total carotenoids content was stable during drying between 50 and 70 °C. Vitamin E showed no significant loss during drying at any of the assayed temperatures, which could be due to its occurrence within the lipid fraction. Drying at 40 °C imparted a darker brown colour to the seaweed, while a lighter brown colour was acquired as drying temperature increased. The greatest loss in total phenolics content occurred at 60 °C, while total flavonoids content showed a significant reduction, which declined as drying temperature increased. According to the experimental results, phenolics and flavonoids could be considered as an important source of bioactive compounds with relatively high antioxidant activity. Thus D. antarctica may satisfy the requirements for development of functional foods.

The aim of this study was to combine high hydrostatic pressure (HHP) and SFE-CO2 to extract bioactive compounds with antioxidant capacity (phenolics and β-carotene) from Cape gooseberry (Physalis peruviana L.) pulp. Extracts were evaluated immediately after processing by HHP at 300–400–500 MPa/1-3–5 min, respectively, and after 60 days of storage at 4 °C. Treatments at 300 MPa/1 min and 400 MPa/3 min showed an increase of antioxidant capacity compared to control untreated samples at day 0. Treatments at 500 MPa presented the highest antioxidant capacity (12388.3 μmol TE/100 g d.m.) after storage. Samples treated at 400 MPa/3 min presented a high content of total phenols at day 60. The highest β-carotene content was observed at 300 MPa/3 min (5.51 mg β-carotene/100 g d.m.). Our results indicate that HHP treatments combined with SFE-CO2 can promote active ingredient release in fruit matrices, increasing their bioactivities, as seen with antioxidant activity. Fil: Torres Ossandón, Maria José. Universidad de La Serena; Chile Fil: Vega Gálvez, Antonio. Universidad de La Serena; Chile Fil: López, Jéssica. Pontificia Universidad Católica de Valparaíso; Chile Fil: Stucken, Karina. Universidad de La Serena; Chile. Instituto de Investigación Multidisciplinario en Ciencia y Tecnología; Chile Fil: Romero, Julio. Universidad de Santiago de Chile; Chile Fil: Di Scala, Karina Cecilia. Universidad Nacional de Mar del Plata. Facultad de Ingeniería. Departamento de Ingeniería Química; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Mar del Plata; Argentina

Five drying methods (freeze, convective, sun, infrared, and vacuum drying) were applied to maqui berries to establish their effect on phenolic compounds and antioxidant capacity. Total phenolic, total flavonoid, and total anthocyanin contents were measured by spectrophotometry, anthocyanin and phenolic profiles were analyzed by chromatography, and the antioxidant capacity was determined. This study is probably the first to demonstrate the variation and stability of bioactive compounds from maqui berries after applying different drying methods.; Results: The highest content of phenolic and antioxidant compounds was obtained by using the freeze-drying method compared with fresh samples (P

Olive oil production in Chile has increased 900% in the last 10 years, resulting in a concomitant increase in waste products that need to be managed. In this study, drying assays were conducted in a convective hot-air dryer on Arbequina olive waste cakes between 40 and 90 °C and a constant airflow of 2 m/s. Proximate composition, dietary fiber, minerals, fatty acids, tocopherols, phytochemicals as well as antioxidant activity as DPPH, FRAP and ORAC values were determined. These six drying temperatures were found to have variable effects on general composition of the residues. Fatty acids were found in high concentration at low temperatures where oleic acid was the most abundant and α-tocopherol was the most prevalent form of vitamin E. The phytochemical content (total phenolics, flavonoids and flavanols) represented an average of 20.7% of the waste cake. Fresh cake showed the highest polyphenols and flavonoids content whereas flavanols content was higher at all drying temperatures. 3-Hydroxytyrosol was the most abundant phenolic compound, and found in higher abundance in samples dried at 90 °C. The antioxidant capacity measured by FRAP and DPPH assays decreased with drying or remained unchanged when measured by ORAC assay. Given the nutritional and commercial potential of waste cakes, a drying technology for the preservation of bioactive compounds from waste products is discussed.

Drying kinetics, proximate composition, dietary fiber, total phenolic compounds, pigments, amino acid profile, and antioxidant capacity (2,2-diphenyl-1-picrylhydrazyl (DPPH) and oxygen radical absorbance capacity) of a red edible seaweed (Pyropia orbicularis) subjected to vacuum drying at five temperatures (40–80 °C) were evaluated. The experimental drying curves were satisfactorily fitted to the Weibull model. The total dietary fiber (TDF) of this seaweed presented a value of 64.37 g (100 g)−1 d.m. The ratio IDF:TDF was 81.1%. The values for protein ranged between 22.34 and 24.92 g (100 g)−1 d.m. in dried seaweed, and His, Thr, and Pro were the most abundant amino acids. The chlorophyll a content was higher than that for chlorophyll b. Total phenolic content (TPC), phycoerythrin and phycocyanin contents, and carotenoid content as well as antioxidant capacity showed an increase at 70 °C. Moreover, at 70 °C, ΔE presented a value of 15.66. Correlations between the TPC and DPPH values (r2 = 0.899) as well as lightness and hue angle (r2 = 0.776) were found during food drying. This work provides important information about the chemical composition and nutraceutical properties of the Chilean edible red seaweed, P. orbicularis. Fil: Uribe, Elsa. Universidad de La Serena; Chile Fil: Vega Gálvez, Antonio. Universidad de La Serena; Chile Fil: Heredia,Valentina. Universidad de La Serena; Chile Fil: Pasten, Alex. Universidad de La Serena; Chile Fil: Di Scala, Karina Cecilia. Universidad Nacional de Mar del Plata. Facultad de Ingeniería. Departamento de Ingeniería Química; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Mar del Plata; Argentina

The aim of this study is to describe the drying kinetics of a murta (Ugni molinae Turcz) berry puree to obtain a fruit leather through mathematical model and determine the effect of different hydrocolloids on the mass diffusion coefficient, activation energy, surface color, and texture profile at different drying temperatures. Three hydrocolloids were used: 1% gelatin, 0.2% carrageenan, and 4% starch at three process temperatures: 50, 60, and 70°C and a formulation without hydrocolloid as control. The hydrocolloids and process temperature influenced the drying time. The mass diffusion coefficient varied depending on the process temperature and hydrocolloids with values between 1.2665 × 10⁻¹⁰ m² s⁻¹ and 4.5341 × 10⁻¹⁰ m² s⁻¹. The Midilli & Kucuk model had a better fit to experimental values. A MANOVA indicated that hydrocolloids and process temperature had a significant effect on color and texture of fruit leather. The process temperature and concentration of hydrocolloids are important factors for drying process design. PRACTICAL APPLICATIONS: Fruit leather is a low humidity product and stable at room temperature. It can be made with surpluses, discards, or mixtures of fruits, being a new alternative of preservation and healthy consumption. The murta berry is a stationary fruit with antioxidant properties hardly been explored at an industrial level and fruit leathers can be a novel production alternative. Hydrocolloids have gelling and stabilizing characteristics. For this reason, they are used to improve the formation of fruit leathers, although it is necessary to know their effects on physical characteristics as color and texture of the final product. These features are important for consumers' purchasing decision. The convective drying process parameters for fruit leather production as: moisture content, diffusion coefficient, and activation energy can be determined by mathematical modeling. The knowledge of these parameters is important for drying process designs.

Green seaweeds are a potential source of proteins, minerals, fatty acids, and essential amino acids, and also often contain bioactive compounds with antioxidant activity. They have the potential to be a source of functional and nutraceutical ingredients. However, their elevated water content shortens shelf life; thus, a preservation method should be employed, such as drying. In the present article, Chilean green seaweed (Ulva spp.) was characterized and the effect of different drying methods (freeze-, vacuum-, solar-, and convective drying) on the quality of dried algae as functional ingredient, along with a description of the drying parameters for each method was evaluated. Proximate composition of fresh Ulva spp. indicated that, other than water, ash, protein, and crude fiber are the main constituents. Ulva samples also had a high amount of total dietary fiber (with an IFD/SFD ~ 1.5). The isotherm curve presented the typical type II sigmoid shape and the BET model gave the best fitting. There was a significant effect of drying method on proximate composition of dried Ulva and the convective drying the method that showed higher values for almost all parameters, except fat content. Color was not affected by drying and the typical green color was present in all samples. Total flavonoid content (TFC), total carotenoids and antioxidant capacity (DPPH and ORAC) were also higher in convective drying. In addition, other minor components with nutritional value were identified, such as essential polyunsaturated fatty acids (PUFAs with a ω3/ω6 ratio of 1:1) and amino acids. Among the different drying methods applied, convective drying (70 °C, 120 min) better retained the physicochemical parameters and antioxidant capacity of Ulva spp. Fil: Uribe, Elsa. Universidad de La Serena; Chile Fil: Vega Galvez, Antonio. Universidad de La Serena; Chile Fil: García, Vivian. Universidad de La Serena; Chile Fil: Pasten, Alexis. Universidad de La Serena; Chile Fil: López, Jéssica. Pontificia Universidad Católica de Valparaíso; Chile Fil: Goñi, María Gabriela. Universidad Nacional de Mar del Plata. Facultad de Ingeniería. Departamento de Ingeniería Química. Grupo de Investigación en Ingeniería en Alimentos; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Mar del Plata; Argentina

Low-Temperature Vacuum Drying (LTVD) could be considered an alternative to conventional food drying methods at high temperature in preserving bioactive compounds from foods. Thereby, the aim of this work was to evaluate the antioxidant and antimicrobial potential of papaya (Vasconcellea pubescens) pulp after LTVD compared to other drying methods including freeze-drying (FD), vacuum-drying (VD), convective-drying (CD) and infrared-drying (IRD). The drying rate was significantly influenced by the drying methods and temperatures. Compared with FD, LTVD resulted in a 52% decrease in drying time. Both disk-diffusion and minimal inhibitory concentration (MIC) assays showed increased antimicrobial activity for extracts prepared with dehydrated papaya. The lowest MIC (15.6 mg mL−1) was found against Bacillus cereus for extracts prepared with VD, CD and IRD papaya. All antioxidant compounds tested decreased after dehydration; however, a strong correlation was observed between DPPH and the antimicrobial activity against E. coli and B. cereus for all extracts prepared with dried papaya pulp. Therefore, dried papaya extracts can be good candidates for the development of natural preservatives regardless of the drying method used. Industrial relevance: Low-temperature vacuum dehydration (LTVD) is a novel technology that was initially developed for the drying of sensitive food ingredients. However, it is unknown if this technique can protect the heat sensitive antimicrobial compounds of fruits.

A 3D model considering heat and mass transfer for food dehydration inside a direct contact dryer is studied. The k– e model is used to describe turbulent air flow. The samples thermophysical properties as density, specific heat, and thermal conductivity are assumed to vary non-linearly with temperature. FVM, SIMPLE algorithm based on a FORTRAN code are used. Results unsteady velocity, temperature, moisture, kinetic energy and dissipation rate for the air flow are presented, whilst temperature and moisture values for the food also are presented. The validation procedure includes a comparison with experimental and numerical temperature and moisture content results obtained from experimental data, reaching a deviation 7–10 %. In addition, this turbulent k– e model provided a better understanding of the transport phenomenon inside the dryer and sample.

The purpose of this study was to investigate the effect of temperature in the vacuum drying process of Mentha piperita L. (50 to 90 °C). Generally, drying processes affect the quality of product, however, vacuum drying works under sub-atmospheric pressures. In order to investigate how temperature affects this herb, as to color, chlorophyll, total phenolic (TPC), total flavonoid (TFC) contents, antioxidant activity by DPPH and ORAC methods. Mineral, vitamin C and sugar contents were also evaluated. A slight change in color and chlorophyll content was observed in the samples. The highest values for TPC, TFC and antioxidant activity methods were obtained at 50 and 70 °C however, a decrease in the vitamin C content was observed. Minerals such as K, Ca, Mg and Na were found. Sucrose showed the highest sugar content. This work suggests that M. piperita L. can be used as a natural antioxidant, whether fresh or dried.

Thermal processing is known to affect the content of the bioactive compounds and antioxidant activity. In this study drying assays were conducted on maqui berries (Aristotelia chilensis) between 40 and 80 °C and a constant airflow of 2 m/s. Total phenolics, flavonoids, anthocyanin, free and bound phenolic acids, β-carotene, tocopherols, vitamin B as well as antioxidant activity as ORAC and DPPH values were determined. Evaluation of drying behaviour showed that at 80 °C equilibrium moisture content is reached after 300 min, while at 40 °C a drying time of 1080 min is needed, whereby degradation of bioactivity is more affected by the higher thermal load, which is observed on the berries at lower temperature. The content of total phenolics was found highest at 60 °C, while that of total flavonoids was highest at 70 °C, with a better correlation to DPPH values compared to ORAC values. The degradation behaviour of α- and γ-tocopherol, was also investigated and resistance to degradation was found highest at 70 °C. Results of the present study provide a valuable tool to harness drying process of maqui berries.

The aim of this investigation was to determine the effect of high hydrostatic pressure (HHP) on dietary fiber, total phenolic (TPC), Vitamin B and E contents, antioxidant capacity (AC) and microbiological characteristics of gooseberry pulp immediately after processing (300-400-500 MPa/1-3-5 min) and after 30 days of storage at 4 °C. Initially, treatment at 300 MPa/1 min reduced the microbial counts to non-detectable levels (

Stevia leaves are usually used in dried state and undergo the inevitable effect of drying process that changes the quality characteristics of the final product. The aim of this study was to assess temperature effect on Stevia leaves through analysis of relevant bioactive components, antioxidant capacity and content of natural sweeteners and minerals. The drying process was performed in a convective dryer at constant temperatures ranging from 30 to 80 °C. Vitamin C was determined in the leaves and as expected showed a decrease during drying proportional to temperature. Phenolics and flavonoids were also determined and were found to increase during drying below 50 °C. Antioxidant activity was determined by DPPH and ORAC assays, and the latter showed the highest value at 40 °C, with a better correlation with the phenolics and flavonoids content. The content of eight natural sweeteners found in Stevia leaves was also determined and an increase in the content of seven of the sweeteners, excluding steviol bioside, was found at drying temperature up to 50 °C. At temperatures between 60 and 80 °C the increase in sweeteners content was not significant. Stevia leaves proved to be an excellent source of antioxidants and natural sweeteners.

Wheat gluten foams containing additives, such as zein, pine wood, and calcium carbonate, (CaCO3) were produced using a heated mold. The foams’ properties were characterized using compression testing, differential scanning calorimetry, Fourier Transform Infra-red (FTIR) spectroscopy, thermogravimetric analysis, X-ray diffraction, and scanning electron microscopy (SEM). FTIR spectroscopy results indicated that foams were more aggregated than gluten powder. The addition of zein, pine wood, and CaCO3 led to significant increases in compressive modulus and strength values. The sample containing 10 wt% pine wood had the highest modulus value of 4.46 ± 0.16 MPa and the sample containing 5 wt% CaCO3 had the highest strength value of 0.40 ± 0.2 MPa. SEM micrographs showed compatibility of gluten with pine wood and CaCO3, which indicated effective stress transfer between gluten matrix and additives. Also, the foams had water uptake values that were more than two times that of gluten powder.

Refractance window drying (RWD) is a novel drying technique, in which heat transfer is by conduction and radiation. In this study, RWD technique has been performed in a static mode at a temperature of 70 °C that is lower than that used in common practice, which led to a consequently prolonged drying time of 180 min to reach equilibrium. Goldenberry (Physalis peruviana L.) pulp was dried under these RWD conditions and several quality characteristics were assessed and compared to the products from freeze-drying, convective drying and infrared radiation drying. It was found that RWD even under a prolonged drying time produced a high-quality product, comparable in many aspects to freeze-dried products; total phenolics contents were not significantly different, while total flavonoid and total carotenoid contents were only slightly lower. RWD samples maintained a color closer to that of the fresh sample than did freeze-dried product. Antioxidant activity determined by DPPH and ORAC assays was maintained at a high level. Amino acid profiles of RWD and freeze-dried samples were similar. The capacity of RWD samples to inhibit α-glycosidase is of the same order as displayed by the dried products from the other drying techniques.

The use of growth promoting bacteria in sweet pepper plants (Capsicum annuum), such as some Bacillus strains, has previously been related to increased yields and plant resistance. However, it is also important to evaluate the effect that inoculation has on the ripening process and on the nutritional composition of the fruits. In the present work, the effect of root inoculation of sweet pepper plants with Bacillus amyloliquefaciens on the composition of sweet peppers harvested at different stages of maturation is evaluated. It was possible to determine a clear effect of inoculation on the fixation of Ca and Fe, and the content of vitamin C and compounds with antioxidant capacity. Root inoculation with Bacillus amyloliquefaciens generated an increase in the concentration of calcium, iron and vitamin C of 561 mg kg−1, 182 mg kg−1 and 561 μg 100 g−1 d.m., respectively in Red II and Green I compared to the control samples. An increase in antioxidant capacity was generated, which is reflected in an increase in the ORAC test of 1618 umol TE 100 g−1 d.m. and in 587 umol TE 100 g−1 d.m. for Green I and Red I crops respectively. On the other hand, the effect of the fruit ripening process was significant, especially in relation to the development of natural pigments and phenolic compounds, with high antioxidant potential. An increased of extractable pigments of 57 color units with respect to the control sample in Red II is highlighted, which enhances the organoleptic attractiveness of the fruit. These results would allow producers to determine the time at which to harvest to maximize the nutritional contribution of sweet peppers.

The aim of this study was to evaluate dehydrated murta berries enriched with probiotic (Lactobacillus casei var. rhamnosus) bacteria. L. casei was incorporated to fresh murta by vacuum impregnation at alternative conditions (pressure 50, 150 and 300 mbar; time 5, 10 and 15 min; temperature 20 ± 0.2 °C) and impregnated murta samples were dehydrated by two drying methods at 40 °C, vacuum and convective drying. Both drying processes were modeled by three mathematical models (Weibull, Page and modified Page). According to the statistical tests applied, the Weilbull model obtained the best-fit quality on experimental data. Effective moisture diffusivity varied between 1.23–1.75 × 10(−10) m(2)/s and 1.16–1.44 × 10(−10) m(2)/s for vacuum and convective drying, respectively. After impregnation, murta berries contained approximately 10(7) CFU/g L. casei although maximum counts were found at 150 mbar for 15 min. Drying decreased L. casei viability in 1.5–1.9 log and 0.5–1.2 log for vacuum and convective drying, respectively. Thus, impregnation at 150 mbar for 15 min followed by convective drying at 40 °C appears as the method of choice to produce probiotic enriched murta berries that can be commercialized as probiotic dried snacks.