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Green-ripe pineapples are shipped overseas by sea freight, while those picked at full maturity need to be transported by airfreight over the same large distance. In this study, fresh-cut pineapple cubes were assessed two, five, and eight days after processing from green-ripe pineapples after mimicked sea freigh (SF) and fully ripe air-freighted (AF) pineapples. The sea-freighted samples displayed elevated titratable acidity (TA), thus resulting in smaller ratios of total soluble solids and TA compared to the AF pineapples. Differences in the carotenoid levels of the two fresh-cut categories were found to be insignificant. By contrast, hierarchical cluster analysis (HCA) and principal component analysis (PCA) calculated on the basis of the volatiles analysed by headspace solid-phase microextraction–gas chromatography–mass spectrometry (HS-SPME–GC–MS) permitted to distinguish all six individual sample types and to segregate them into two major clusters (SF and AF). The effect of storage on the volatiles was further evaluated by partial least squares (PLS) regression. Substantial chemical markers to differentiate the individual samples and to describe the effect of storage were deduced from the PCA and PLS regression, respectively. In general, fresh-cut products obtained from fully ripe AF fruit displayed higher concentrations of volatiles, in particular, increased concentrations of diverse methyl esters. With progressing storage duration, the concentrations of ethanol and diverse ethyl esters increased. Moreover, products from AF pineapples displayed lower microbial counts compared to those from SF fruit.

A comprehensive study using continuous pressure change technology (PCT) for the non-thermal processing of fresh pineapple juice on pilot scale was conducted (1 L/min, 50 MPa, argon, 3 min, L*a*b*). A significant reduction in the mean particle size resulted in diminished centrifugable pulp contents and enhanced cloud stability. Moreover, a slightly improved microbial quality (−0.9 to −1.2 log10 CFU/mL) in terms of total aerobic and yeast and mould counts was attained. Noteworthy, PCT retained a high bromelain activity (−3 to −15% reduction) and efficiently inactivated polyphenol oxidase. Water-soluble vitamins, phenolic compounds, and all further constituents assessed were mostly preserved. However, the high residual peroxidase activity (−10 to −23%) and microbial loads are likely to affect juice quality during storage. In contrast, thermal pasteurisation ensured a complete reduction in both microbial counts (−4.4 to −4.5 log10 CFU/mL) and effective inactivation of peroxidase. However, bromelain activity was strongly affected (−83%) by heat treatment, and colour was darkened and even less yellowish. Overall, this study highlighted the potential of PCT for the production of fresh-like pineapple juices; however, its current limitations were revealed as well.

The effect of pulsed light (PL) on numerous important quality characteristics of pineapple juice was studied and compared with untreated and thermally pasteurised samples. The laboratory scale PL batch system used was operated with each three different voltages (1.8, 2.1, and 2.4 kV) and numbers of pulses (47, 94, and 187). Treatments with 2.4 kV and either 94 or 187 pulses (757/1479 J·cm−2) resulted in a 5-log reduction in aerobic mesophiles and the yeast and mould counts. Peroxidase was more resistant to PL than polyphenol oxidase, whereas the bromelain activity was completely retained in all PL-treated juices. Colour and antioxidant capacity were minimally affected, while vitamin C, genuine pineapple furanones, and phenolic compounds declined. In contrast, thermal pasteurisation was more detrimental to colour, antioxidant capacity, and vitamin C content, but resulted in a superior inactivation of microorganisms and enzymes and retention of phenolic compounds. Principal component analysis (PCA) permitted the differentiation of fresh, thermally pasteurised, and all PL-treated juices. PCA on the basis of the individual juice constituents additionally arranged the latter juices according to the number of pulses and voltage levels applied, particularly promoted by the oxidation of ascorbic to dehydroascorbic acid. In conclusion, PL treatment represents a promising new alternative to conventional thermal preservation techniques, whereby the inactivation of deteriorative enzymes may be further optimised.

Total lipids, fatty acids and triacylglycerols in seeds of the four Saudi Arabian date cultivars ‘Anbra’, ‘Megadwel’, ‘Sacai’ and ‘Sfwai’ were analysed. Total lipid contents ranged between 7.3 and 8.6%. Oleic, lauric and myristic acid represented the most abundant fatty acids in date seed oil. HPLC‐DAD‐ESI‐MSⁿ analysis enabled the identification of 40 triacylglycerols with equivalent carbon number (ECN) 36–54, of which 17 were detected for the first time. Triacylglycerols mainly comprised LaOL, LaLaL, LaML, MML/LaPL and LaOO. ‘Anbra’ oil was characterised by highest proportions of saturated fatty acids and triacylglycerols with ECN 36 and 48–54. Unsaturated fatty acids prevailed in the three remaining varieties. Elevated proportions of triacylglycerols with medium ECNs were found in ‘Megadwel’ and ‘Sfwai’ oils. Aside from highest total lipid contents, ‘Sacai’ seeds predominantly contained triacylglycerols with low ECNs. Multivariate statistical analyses elucidated varietal influences on the fatty acid and triacylglycerol composition of date seed oil.

Corn (Zea mays L.) growth and development is often limited by the availability of phosphate. We thus hypothesized that phosphate fertilization may increase the contents of (poly)phenols, carotenoids, and tocochromanols (vitamin E) in corn grains. Corn plants cultivated on a soil fertilized with 44 kg phosphorus/ha were compared to plants grown on soil with low plant-available phosphate (1.6 mg CAL-P/100 g of soil), each sown early (April) and late (May) in a randomized field experiment. HPLC-DAD-(HR)-ESI-MSn revealed 19 soluble and 10 insoluble (poly)phenols, comprising phenolic acids, phenolic amines, diferulic, and triferulic acids in corn grains. Contents of individual (poly)phenols, carotenoids, and tocochromanols in whole grains were significantly (p < 0.05) increased by sowing time, but not by phosphate fertilization. In conclusion, low phosphate availability did not impair the biosynthesis of (poly)phenols, carotenoids, and tocochromanols in corn grains.

Similarities among nutritionally relevant carotenoid profiles in red- and yellow-fleshed papaya (Carica papaya L.) cultivars were revealed using liquid chromatography coupled to mass spectrometry. Differences were observed mainly in lycopene content. Where yellow papayas contain only trace amounts of lycopene, it is the predominant carotenoid in red papayas. Chromoplast morphology and ultrastructure of red- and yellow-fleshed papayas were investigated using light and transmission electron microscopy. Carotenoids in yellow papaya were deposited in tubular plastids, while crystalloid substructures in red papaya chromoplasts were associated with lycopene accumulation. Carotenoid deposition may be relevant to its bioavailability. Therefore, this parameter was compared among papaya, carrot, and tomato using 16 healthy human subjects for a randomized crossover study. Test meals were adjusted in order to deliver equal amounts of β‑carotene and lycopene. Triacylglycerol-rich lipoprotein fractions were analyzed for 9.5 hours after test meal consumption. β‑Carotene of papayas was approximately three times more bioavailable than that of carrots and tomatoes. Moreover, lycopene bioavailability in papayas was approximately 2.6 times higher than that of tomatoes. Bioavailability of β‑cryptoxanthin from papayas was higher when compared with the other papaya carotenoids, β‑carotene and lycopene, respectively 2.9 and 2.3 times higher. Liquid-crystalline deposition of β‑carotene and the storage of lycopene in very small crystalloids in papayas may play an important role in improving the bioavailability of such carotenoids when compared with other deposition forms.

Mamey sapote is a fruit rich in specific keto-carotenoids, namely sapotexanthin and cryptocapsin. Their chemical structure suggests their provitamin A activity, although their absorption and conversion to vitamin A remained to be demonstrated in humans. Besides structure-related factors, the fruit matrix might also hamper absorption and conversion efficiency. Therefore, we monitored carotenoid and vitamin A levels in triacylglycerol-rich lipoprotein (TRL) fractions in plasma of human participants after consumption of fresh sapote and a carotenoid-rich “matrix-free” formulation derived thereof. A randomized 2-way cross-over study was conducted to compare the post-prandial bioavailability of 0.8 mg sapotexanthin and 1.2–1.5 mg cryptocapsin from the above-mentioned test meals. Seven blood samples were drawn over 9.5 h after test meal consumption. Carotenoids and retinoids were quantitated in TRL fractions using HPLC-DAD. Sapotexanthin was absorbed by all participants from all meals, being ca. 36% more bioavailable from the “matrix-free” formulation (AUCmedian = 73.4 nmol∙h/L) than from the fresh fruit (AUCmedian = 54.0 nmol∙h/L; p ≤ 0.001). Cryptocapsin was only absorbed by 4 of 13 participants. The appearance of retinyl esters was observed in all participants independent of the test meal. Although the fruit matrix hampered carotenoid in vivo-bioavailability from sapote, the fruit clearly represents a valuable source of vitamin A for humans. German Academic Exchange Service/[]/DAAD/Alemania UCR::Vicerrectoría de Investigación::Unidades de Investigación::Ciencias Agroalimentarias::Centro Nacional de Ciencia y Tecnología de Alimentos (CITA) UCR::Vicerrectoría de Docencia::Ciencias Agroalimentarias::Facultad de Ciencias Agroalimentarias::Escuela de Tecnología de Alimentos UCR::Vicerrectoría de Investigación::Unidades de Investigación::Ciencias Agroalimentarias::Centro de Investigación en Nutrición Animal (CINA) UCR::Vicerrectoría de Docencia::Salud::Facultad de Medicina::Escuela de Medicina

The aim of the present article was an in-depth characterization of cyanidine-rich red cabbage extracts and the identification of challenges emerging during the purification of their pigments. Two extraction procedures using either hot acidified or temperate water at its genuine pH were compared. LC-MS analyses revealed 20 mostly acylated anthocyanins, five aliphatic glucosinolates, and four indolic glucosinolates as non-volatile constituents. In addition, volatiles were characterized by HS-SPME-GC-MS. Whereas the glycosidic precursors do not impair the sensory properties, their enzymatic degradation products may evoke unpleasant flavors. The crude pigment extract obtained with hot acidified water contained low concentrations of C6 aldehydes, isothiocyanates, nitriles, and sulfides, and was selected for purification experiments. Amberlite XAD 16 HP, polyamide, chitosan, and lignosulfonate were used as adsorbents and flocculants. Particularly, Amberlite and lignosulfonate treatment diminished the content of glucosinolates and volatiles. Interestingly, indolic glucosinolates and acylated anthocyanins showed similar behavior in all purification procedures performed.

Total lipids, fatty acids, and triacylglycerols in mesocarp and kernels from Costa Rican Acrocomia aculeata fruits were characterized at three maturity stages. C16:0 and C18:1n9 were the most abundant fatty acids in the mesocarp. C12:0, C14:0, C16:0, and C18:1n9 prevailed in the kernel oil. Comprehensive HPLC-DAD-APCI-MS and ESI-MSn analysis revealed 125 triacylglycerols with equivalent carbon numbers ranging between 28 and 52. Mesocarp oils mainly contained unsaturated triacylglycerols composed of long-chain fatty acids. In the kernel, high proportions of saturated triacylglycerols with medium-chain fatty acids were observed. Within the maturity stages assessed, fatty acid and triacylglycerol compositions remained unaffected by ripening. Total lipids in the mesocarp increased from 12.1 to 23.4% with progressing maturity, whereas those in the kernel constantly ranged between 54.1 and 56.1%. For the recovery of A. aculeata oil, utilization of all fruits in a bunch at progressed maturity is possible without affecting the composition of its major lipid fractions. UCR::Vicerrectoría de Investigación::Unidades de Investigación::Ciencias Agroalimentarias::Centro para Investigaciones en Granos y Semillas (CIGRAS) UCR::Vicerrectoría de Docencia::Ciencias Agroalimentarias::Facultad de Ciencias Agroalimentarias::Escuela de Tecnología de Alimentos UCR::Vicerrectoría de Investigación::Unidades de Investigación::Ciencias Agroalimentarias::Instituto de Investigaciones Agrícolas (IIA)

BACKGROUND This follow-up study evaluated microbiome changes in periodontal recall patients after consuming a nitrate-rich diet that led to a marked decrease of gingival inflammation. METHODS Subgingival microbial samples of 37 patients suffering from gingival inflammation with reduced periodontium were taken before professional mechanical plaque removal (baseline) and subsequently after 2 weeks of regularly consuming a lettuce juice beverage (day 14) containing a daily dosage of 200 mg of nitrate (test group, n = 18) or being void of nitrate (placebo group, n = 19). Three hundred base pairs paired-end sequencing of the V3-V4 hypervariable region of the 16S rDNA was performed. RESULTS At baseline, there were no significant differences about the bacterial diversity parameters between the groups (Mann-Whitney U test). After intervention in the test group, Rothia and Neisseria, including species reducing nitrate, increased significantly (negative binomial regression model). Alpha diversity decreased significantly from 115.69 ± 24.30 to 96.42 ± 24.82 aRSVs/sample (P = 0.04, Wilcoxon signed-rank test), accompanied by a significant change in beta diversity (P < 0.001, PERMANOVA). In the control group, however, no genus changed significantly, and alpha-, as well as beta-diversity did not change significantly. CONCLUSIONS The decrease of gingival inflammation in periodontal recall patients induced by a nitrate-rich diet is accompanied by significant compositional changes within the subgingival microbiome.

Anthocyanins, betalains, carotenoids, and chlorophylls confer the attractive colors of plant-derived foods. These natural pigments, however, are unstable and prone to chemical changes during processing and storage, resulting in loss of color and biological activities. Anthocyanins suffer hydrolysis, nucleophilic attack by water, ring cleavage, and polymerization. Betacyanins undergo hydrolysis, C15 isomerization, dehydrogenation, and decarboxylation. Carotenoids are susceptible to geometric isomerization, epoxidation, and cleavage to apocarotenals and, eventually, to volatile compounds. Chlorophylls are epimerized and transformed to pheophytin, pyropheophytin, chlorophyllide, pheophorbide, and pyropheophorbide. The factors that enhance or inhibit these chemical alterations have been widely investigated. Considering the importance of these pigments to food quality and their potential health-promoting effects, the wealth of knowledge that has been accrued should be used to guarantee retention of these valuable compounds during processing and storage of food.

So far, the occurrence of the flavor constituent 1-phenylethyl acetate in a natural source has not been unambiguously confirmed. The present work provides the detailed identification of 1-phenylethyl acetate from clove (Syzygium aromaticum (L.) Merr. & L.M. Perry) buds. In addition, headspace solid-phase microextraction-gas chromatography/mass spectrometry (GC/MS) analysis revealed further occurrence of 1-phenylethyl acetate in cocoa pulp and grape hyacinth flowers. A total of 15.2 g of essential oil was recovered from 7.2 kg of clove buds by simultaneous distillation-extraction followed by vacuum distillation. The distillate obtained was fractionated by silica column chromatography, whereby a significant enrichment of 1-phenylethyl acetate was achieved. The fraction containing the target analyte was further purified by preparative high-performance liquid chromatography, resulting in a final purity of ∼93.0%, yielding a total of 1 to 2 mg of 1-phenylethyl acetate. Identification of the isolated compound was achieved by GC/MS, infrared spectroscopy, enantioselective GC, isotope ratio MS, and nuclear magnetic resonance spectroscopy. Enantioselective GC/MS analysis revealed an enantiomeric excess of 60% (1S)-(-)-1-phenylethyl acetate in the isolate. The δ13CV-PDB value of -32.5 ± 0.5‰ was in accordance with that of C3-plants and other constituents found in genuine clove extracts.

In orange-pigmented citrus fruits, the xanthophyll esters are the predominant carotenoids, but their biosynthetic origin is currently unknown. In this work, seven PYP/XES (Pale Yellow Petal/ Xanthophyll esterase) genes were identified in Citrus genomes, but only PYP1-4 and 6 contained the structural domains essential for activity. The PYP/XES expression profiles in sweet orange and in other Citrus species such as lemon, mandarin and pummelo with marked differences in fruit pigmentation and content of xanthophylls esters, showed the upregulation of PYP1,2 and 6 genes during ripening only in orange-pigmented fruits. Moreover, transcript levels of PYP1, 2 and 6 genes in peel and pulp of sweet orange were accompanied by the accumulation of xanthophyll esters during ripening. This work reports for the first time the PYP/XES gene family in Citrus and strongly suggests its involvement in xanthophyll esterification in citrus fruit tissues and its influence in carotenoid accumulation and fruit pigmentation., This work was supported by the Ministry of Science, Innovation and Universities, Spanish Government (research grant RTI2018-095131-B-I00). J. Zacarias is the recipient of predoctoral scholarship from Generalitat Valenciana (grant number FDEGENT/2018/007). The authors acknowledged the Citrus Germplasm Bank (IVIA, Moncada, Spain) and ANECOOP for the provision of fruits and other plant material. The technical assistance of I. Carbonell and Mª C. Gurrea is gratefully acknowledged. Authors are members of Eurocaroten (COST_Action CA15136) and CaRed (Spanish Carotenoid Network, BIO2017-90877-REDT).

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Analysis of pulp and peels of Arabica coffee varieties with different external fruit color allowed the identification of 16 phenolic compounds using high-performance liquid chromatography with diode array detection and electrospray ionization multi-stage mass spectrometry (HPLC-DAD-ESI-MSn ). Nine chlorogenic acids, three flavan-3-ols, the xanthone mangiferin, the flavonol rutin and two anthocyanins were tentatively identified and quantified. 5-O-Caffeoylquinic acid together with a putative (epi)catechin hexoside were the predominant phenolics detected in the coffee varieties analyzed in this work. Whereas, 3- and 4-caffeoylquinic acids, as well as 5-O-feruloylquinic acid were consistently found in higher quantities in the pulp than in the peels when individual varieties were compared, the opposite was found for the other phenolic compounds detected. Complementary, GC-MS after alkaline hydrolysis and trimethylsilylation permitted the identification of more than 30 constituents, including phenolic compounds and other benzenoids, caffeine, and diverse carboxylic acids. Detected anthocyanins were cyanidin-3-O-glucoside and cyanidin-3-O-rutinoside. Anthocyanin contents in orange-colored berries were lower than those in red fruits, while no anthocyanins were found in yellow-colored fruit. Among non-anthocyanin pigments, we found β-carotene and lutein in all varieties, along with other chloroplast-specific carotenoids in some accessions. In addition, saponification evidenced the presence of several xanthophyll esters. Both, chlorophyll a and b, were detected in the peels of all varieties, while only chlorophyll b was observed in the pulp. Thus, the color of yellow-peeled varieties is due to carotenoids, while that of orange and red-peeled varieties is due to both carotenoids as well as low and high levels of anthocyanins, respectively. Present results point out to the potential use of by-products of particular coffee varieties with differences in the external fruit color as a source of distinctive bioactive compounds, including anthocyanins and carotenoids, with health benefits. Universidad de Costa Rica/[735-C0-750]/UCR/Costa Rica UCR::Vicerrectoría de Investigación::Unidades de Investigación::Ciencias Agroalimentarias::Centro para Investigaciones en Granos y Semillas (CIGRAS) UCR::Vicerrectoría de Docencia::Ciencias Agroalimentarias::Facultad de Ciencias Agroalimentarias::Escuela de Tecnología de Alimentos UCR::Vicerrectoría de Investigación::Unidades de Investigación::Ciencias Agroalimentarias::Instituto de Investigaciones Agrícolas (IIA)

The composition of soluble carbohydrates such as fructooligosaccharides (FOS) in onions ( Allium cepa L.) plays a role regarding their digestibility, long-term storability, and processability. Qualitative and quantitative profiles of soluble carbohydrates were determined in 23 different onion samples comprising 20 cultivars grown at two different locations in 2014 and 2015. FOS concentrations were 1.1-fold higher in set grown onions than in seed grown onions ( p = 0.001). FOS levels of dehydrator cultivars were higher (overall average: 130.8 ± 42.4 g/L FOS) than those of common set and seed (61.8 ± 20.0 and 29.4 ± 14.7 g/L FOS) grown cultivars. Consequently, cultivation method (seed vs. set planting) and cultivar selection were crucial when aiming at onions with defined FOS contents. Besides FOS and other carbohydrate-related parameters, levels of alk(en)yl cysteine sulfoxides, indicating onion oil yield and pungency of onions, were determined to be different in dehydrator onions (13.1 ± 2.6 μmol/mL), seed (8.4 ± 1.3 μmol/mL), and set grown onions (7.5 ± 1.6 μmol/mL).

Curly parsley is widely applied as a culinary herb. Due to its growth close to ground level and its curly leaf structure, it is inherently affected by high counts of autochthonous microbiota, which may include pathogens. Washing of leaves prior to freezing is the only step in the processing of deep-frozen parsley enabling the reduction of viable counts. Therefore, the aim of the present study was to evaluate the efficiency of the washing water additives Nα-lauroyl-l-arginine ethyl ester (LAE) and lactic acid in comparison to chlorine as well as sole cold and warm water washing regarding their reduction of viable counts as well as their effect on the sensory quality of parsley. LAE reduced total viable counts, those of Pseudomonas spp. as well as Enterobacteriaceae by at least 2.0 log cfu/g, while lactic acid was especially effective against Enterobacteriaceae. Chlorophyll a and b and β-carotene were best retained during deep-frozen storage in products washed with LAE, while differences for nitrate contents and lipoxygenase activities between the different treatments were insignificant. Flavor ratings were highest for lactic acid treated parsley after 6 months of frozen storage. Thus, the investigated wash water additives were superior to chlorine in curly parsley processing.

ZusammenfassungZucker werden heute meist über verarbeitete Lebensmittel aufgenommen. Nur etwa 10 % des jährlichen Zuckerabsatzes in Höhe von ca. 3 Mio. Tonnen gelangt als sogenannter Haushaltszucker an den Verbraucher. Neben den gustatorischen Eigenschaften erfüllen Zucker eine Reihe technologischer Funktionen.Zucker erzeugen Aroma und Farbe, bewirken flüssig-viskose, gelartige und feste Texturen und dienen der Hemmung der Kristallisation und somit der Frisch- und Feuchthaltung von Lebensmitteln. Außerdem verbessern Zucker Haltbarkeit und Farbstabilität und stellen Substrate für die Teiglockerung und zur Gewinnung fermentierter Lebensmittel dar. Einen Überblick zur Thematik geben die Review-Artikel in 1 und 2.

Irvingia gabonensis kernels are a promising oleiferous source. Their total lipid content was 72.3%. C14:0 and C12:0 represented the most abundant fatty acids. Triacylglycerols with ECN 32 and 46–48 were identified for the first time by HPLC‐DAD‐ESI‐MSⁿ. Comprehensive GC‐FID and GC‐MS analyses revealed novel insights into minor lipids like phytosterols and tocochromanols. Among the latter, γ‐tocopherol was found to be the major vitamer. β‐Sitosterol and stigmasterol were the prevailing phytosterols in the kernel fat. The high saturation level of the fat resulted in a sharp differential scanning calorimetry melting curve with a high melting temperature of 42.1 °C. The fat remained solid over a wide temperature range and still contained 66.6% solid fats at 35 °C. Consequently, kernels of the African mango provide a viable source for the recovery of solid fats applicable in the food industry as sustainable alternatives to replace palm‐based fats or hardened vegetable oils.

Carotenoid profiles, by means of HPLC-PDA-MSn, and CIE-L*C*h° colour values of yellow and red nance fruits from Costa Rica were elucidated. Among 16 carotenoids detected, (all-E)-lutein was the most abundant accounting for >80% of the total carotenoids, followed by (all-E)-zeaxanthin (9–11%) and (all-E)-β-carotene (2–9%). Minor constituents were (Z)-isomers of lutein and β-carotene, as well as diverse lutein diesters. Among the esters, lutein dimyristate was the most abundant as substantiated by the comparison with a marigold flower extract. Total carotenoids in the peel (616.2 μg/100 g of FW in yellow nance and 174.2 μg/100 g of FW in red nance) were higher than in the pulp (39.4 μg/100 g of FW in yellow nance and 31.4 μg/100 g of FW in red nance). Since carotenoid profiles of yellow and red varieties were qualitatively similar, although the colour values showed significant differences (77.2 and 88.6 h° in peel and pulp of yellow nance, versus 32.7 and 67.3 h° in peel and pulp of red nance, respectively), pigments other than carotenoids may impart the colour of red nance. High lutein content renders nance fruit as a nutritionally relevant source of this micronutrient. UCR::Vicerrectoría de Docencia::Ciencias Agroalimentarias::Facultad de Ciencias Agroalimentarias::Escuela de Tecnología de Alimentos UCR::Vicerrectoría de Investigación::Unidades de Investigación::Ciencias Agroalimentarias::Instituto de Investigaciones Agrícolas (IIA) UCR::Vicerrectoría de Investigación::Unidades de Investigación::Ciencias Agroalimentarias::Centro para Investigaciones en Granos y Semillas (CIGRAS)

As hydrolysis of carotenoid esters is believed to be highly efficient in vivo, their insufficient hydrolysis in in vitro-digestion models, particularly, regarding zeaxanthin diesters, is a current issue. Therefore, in this study, several factors related to the enzymatic hydrolysis were investigated in an adapted version of the standardized INFOGEST in vitro-digestion model, using zeaxanthin dipalmitate (ZDP) as a substrate. The results showed that pancreatic lipase was able to hydrolyze ZDP, whereas carboxyl ester lipase (CEL) substantially contributed to ZDP cleavage. Replacement of commonly used porcine with bovine bile extracts and the substitution of coffee creamer for soybean oil at identical fat contents both significantly improved hydrolysis efficiency and bioaccessibility of total zeaxanthin to better mimic in vivo conditions. Thus, bile and lipids selection for in vitro digestion of carotenoid esters was crucial. The combined use of coffee creamer, pancreatin, CEL, and bovine bile led to the highest hydrolysis efficiency of 29.5%.

Purpose The purpose of this paper is to provide insight into the consumers’ perception of natural and artificial food colourants. Furthermore, attitudes towards the application of carmine, being technically important and ubiquitously used to impart red shades, are assessed and analysed. Originating from insects, carmine is considered as natural but may arouse disgust. Design/methodology/approach In total, 625 individuals were surveyed using an online, self-administered questionnaire to represent a broad cross-section of the German population. Findings Independent of their origin, the application of colourants was rejected by 57.0 per cent of the interviewees. In total, 31.8 per cent of the participants stated a neutral attitude, while only 11.2 per cent expressed a positive notion. Most respondents preferred colourants from natural sources to artificial ones. While consumers perceive natural food colourants composed of genuine plant pigments positively, 61.6 per cent of respondents disliked the application of animal-derived colourants, 24.8 per cent of them did neither reject nor like it, and only 13.6 per cent of the interviewees stated a positive attitude towards them. The findings of this paper further indicate consumers’ preference for colourants to be either artificial or plant-derived rather than carmine. Food colourants are being rejected, possibly due to misleading information and confusing labelling. Consequently, information about carmine, including its origin and production, did not increase the aversion to products that are dyed with it, but increased their acceptance. Originality/value This study outlines consumer perception and attitudes towards food colourants. For the first time, the findings of this paper report the effect of revealing information about an additive, which initially aroused disgust, and its influence on consumer perception.

Pistachio hulls, important by-products of pistachio processing, were extracted using an environmentally friendly process with subcritical water (SCW) at a pressure of 6.9 MPa in the range of 110 and 190 °C, and a flow rate of 4 ml/min. Detailed HPLC-DAD-ESI/MSn analyses allowed the identification of 49 phenolic compounds in the SCW extracts. Total gallotannin yields up to 33 g/kg were reached at 150–170 °C, where gallic acid (22.2 g/kg) and penta-O-galloyl-β- d -glucose (9.77 g/kg) levels were 13.2- and 10.6-fold higher than those in the aqueous methanol extracts. Flavonols were also effectively extracted at 110–150 °C (4.37–5.65 g/kg), while anacardic acid recovery was poor (1.13–2.77 g/kg). Accordingly, high amounts of anacardic acids (up to 50.7 g/kg) were retained in the extraction residue, revealing that SCW extraction allowed selective extraction of gallotannins and flavonols. Antioxidant capacities ranged from 0.68 to 1.20 mmol Trolox equivalents (TE)/g for SCW extracts increasing with temperature up 190 °C.

Sugar-containing beverages like orange juice can be a risk factor for obesity and type 2 diabetes although the underlying mechanisms are less clear. We aimed to investigate if intake of orange juice with or in-between meals differently affects energy balance or metabolic risk. Twenty-six healthy adults (24.7 ± 3.2 y; BMI 23.2 ± 3.2 kg/m2) participated in a 4-week cross-over intervention and consumed orange juice (20% of energy requirement) either together with 3 meals/d (WM) or in-between 3 meals/d (BM) at ad libitum energy intake. Basal and postprandial insulin sensitivity (primary outcome), daylong glycaemia, glucose variability and insulin secretion were assessed. Body fat mass was measured by air-displacement plethysmography. After BM-intervention, fat mass increased (+1.0 ± 1.8 kg; p ISI: −0.89 ± 2.3; p = 0.06). By contrast, after WM-intervention fat mass and gamma-glutamyl transferase (GGT) decreased (−0.30 ± 0.65 kg; −2.50 ± 3.94; both p p p > 0.05). In young healthy adults, a conventional 3-meal structure with orange juice consumed together with meals had a favorable impact on energy balance, whereas juice consumption in-between meals may contribute to a gain in body fat and adverse metabolic effects.

Carotenoids and tocopherols were characterised in the meso- and exocarp of wild-growing Costa Rican Acrocomia aculeata fruits. Comprehensive profiling of these lipophilic micronutrients in fruits of three varying maturity stages was conducted for the first time. A method for the simultaneous extraction and quantitation of carotenoids and α-tocopherol was developed and validated. Detailed HPLC-DAD-APCI/ESI-MSn analyses enabled the identification of α-tocopherol and 25 carotenoids. The latter comprised antheraxanthin, β-carotene, lutein, luteoxanthin, neoxanthin, phytoene, phytofluene, violaxanthin, zeaxanthin, and several (Z)-isomers of the aforementioned compounds. Quantitation by HPLC-DAD/FLD revealed total carotenoid concentrations of 872 ± 178 and 3075 ± 407 μg/100 g fresh weight in the meso- and exocarp of fully ripe fruits, respectively. In both fruit fractions, progressing maturation resulted in the accumulation of phytoene, phytofluene, (all-E)-zeaxanthin, (all-E)-antheraxanthin, and (all-E)-violaxanthin. Carotenoid profiling was supported by multivariate data analysis. Carotenoid precursors and xanthophyll cycle pigments characterised Macauba fruits of full maturity. UCR::Vicerrectoría de Docencia::Ciencias Agroalimentarias::Facultad de Ciencias Agroalimentarias::Escuela de Tecnología de Alimentos UCR::Vicerrectoría de Investigación::Unidades de Investigación::Ciencias Agroalimentarias::Centro para Investigaciones en Granos y Semillas (CIGRAS)

Onions (Allium cepa L.), grown from seeds and sets were stored in two separate warehouses for 5 months, either under forced air ventilation or cold temperature conditions. Storage carbohydrates including fructo-oligosaccharides (FOS) were quantitated monthly by anion exchange chromatography with pulsed amperometric detection. Set grown onions cv. ‘Sturon’ exhibited highest FOS concentrations after harvest (71.0 ± 19.9 g/L), surpassing those of their seed grown counterparts (43.0 ± 2.7 g/L). Although FOS degraded in both set and seed grown onions during storage, their concentrations remained higher in set grown onions throughout 5 months of storage. However, differences in retention between the levels of storage carbohydrates in cold stored onions and those of onions stored under forced ventilation were insignificant. In brief, while the studied storage conditions were widely irrelevant, propagation method and cultivar selection were found to be of utmost importance for the retention of storage carbohydrates during long-term storage.

To exploit the full potential of industrial mango peel waste (MPW 0 ) as a starting material for the recovery of bioactive and functional coproducts despite its seasonality, it must be processed efficiently into a storable dried byproduct of uniform high quality, irrespective of impacts of different cultivars and ripeness. The focus of this feasibility study, performed on the pilot plant scale, was on technological options for three key process stages in the manufacture of dried mango peel (DMP) as a possible bulk commodity: fruit blanching, peel drying, and DMP packaging. Depending on cultivars, hot-water blanching of fruit (65–85 °C) before peeling proved inappropriate for peel color retention, but could even induce enzymatic browning until peel drying, and thus losses of bioactive compounds due to oxidative polymerization and insolubilization. Hence, this process step should be limited to brief washing of the fruit at maximally 65 °C to reduce microbial load. Intermittent microwave-convective drying (IMWC) of MPW 0 in a continuous belt dryer at high peel throughput was feasible at ambient air temperatures. Finalizing initial IMWC of MPW 0 by convective drying (CD, 80 °C) in the falling-rate period avoided local charring. Alternatively, MPW 0 had to be washed before IMWC to remove adherent pulp, but at the expense of soluble solids and β -carotene losses. Unlike the carotenoids, alk(en)ylresorcinols were hardly affected by IMWC. By washing MPW 0 , quality defects compared to CD-dried peel in terms of antioxidant capacity, water-holding capacity, and yield and quality of pectin were compensated. Adequate preprocessing plus IMWC was thus deemed to be a promising option, especially for biorefinery concepts including biogas production and congeneration. The minimal moisture barrier properties needed for flexible intermediate bulk containers were estimated from an 11-month shelf-life test of IMWC-dried peel in two climate zones.

Carotenoid bioavailability from plant and animal food is highly variable depending on numerous factors such as the physical deposition form of carotenoids. As the carotenoid zeaxanthin is believed to play an important role in eye and brain health, we sought to compare the human bioavailability of an H-aggregated with that of a J-aggregated deposition form of zeaxanthin encapsulated into identical formulation matrices. A randomised two-way cross-over study with sixteen participants was designed to compare the post-prandial bioavailability of an H-aggregated zeaxanthin and a J-aggregated zeaxanthin dipalmitate formulation, both delivering 10 mg of free zeaxanthin. Carotenoid levels in TAG-rich lipoprotein fractions were analysed over 9·5 h after test meal consumption. Bioavailability from the J-aggregated formulation (AUC=55·9 nmol h/l) was 23 % higher than from the H-aggregated one (AUC=45·5 nmol h/l), although being only marginally significant (P=0·064). Furthermore, the same formulations were subjected to an internationally recognisedin vitrodigestion protocol to reveal potential strengths and weaknesses of simulated digestions. In agreement with our human study, liberation of zeaxanthin from the J-aggregated formulation into the simulated duodenal fluids was superior to that from the H-aggregated form. However, micellization rate (bioaccessibility) of the J-aggregated zeaxanthin dipalmitate was lower than that of the H-aggregated zeaxanthin, being contradictory to ourin vivoresults. An insufficient ester cleavage during simulated digestion was suggested to be the root cause for these observations. In brief, combining ourin vitroandin vivoobservations, the effect of the different aggregation forms on human bioavailability was lower than expected.

Anthocyanin profiles and contents of three purple sweet potato provenances were investigated by HPLC-DAD-MSn. In contrast to widely uniform profiles, the contents of total (558-2477mg/100gDM) and individual anthocyanins varied widely. Furthermore, quantitative and qualitative effects of intermolecular co-pigmentation were studied by adding chlorogenic and rosmarinic acids, and food-grade phenolic apple and rosemary extracts at various dosages to a diluted purple sweet potato concentrate at pH 0.9, 2.6, 3.6, and 4.6. Addition of co-pigments generally increased pKH estimate-values of anthocyanins from 3.28 (without co-pigments) to up to 4.71, thus substantially broadening the pH range wherein colored forms prevail. The most pronounced hyperchromic shift by up to +50.5% at the absorption maximum was observed at pH 4.6. Simply by blending the co-pigments with purple sweet potato anthocyanins at pH-values ranging from 2.6 to 4.6, purplish-blue, light pink, magenta, brick-red, and intense red hues were accessible as expressed by CIE-L∗a∗b∗ color values.

Three methods for the recovery of purified pectins from directly dried mango peel were developed, using selective precipitation of mango pectin in propan-2-ol (IPA) of adequate volume concentrations for purification. Yields, composition, macromolecular and gelling properties of the resultant pectins were compared. Effluent analyses proved postextractive removal of fruit exudate arabinogalactans. The recovery processes involved ( A ) washing of raw-pectin powder in IPA of defined volume concentration, ( B ) fractional alcoholic precipitation of dissolved raw pectin, or ( C ) selective pectin precipitation from the hot-acid extract of mango peel in adequately diluted IPA. High galacturonic acid contents (≥ 721 g/kg) and intrinsic viscosities (≥ 320 mL/g) enabled ∼2.2-fold gelling capacities compared to raw mango pectin, which resulted from the standard procedure mimicking industrial pectin recovery from established sources. Removal of the predominant impurities (coextractable exudate arabinogalactans, ash) diminished the yields to ∼49% of the raw-pectin yield. Technical feasibility of the proposed procedures was discussed.

Fructooligosaccharides (FOS) in foods are controversially discussed due to their probiotic activity and their putative contribution to the irritable bowel syndrome (IBS). Besides their nutritional relevance, the genuine composition of carbohydrates in onions has high impact on non-enzymatic browning during thermal processing of onions. In the present study, a method based on high performance anion exchange chromatography with pulsed amperometric detection (HPAEC-PAD) was validated and compared to an ultra-high performance liquid chromatographic method using evaporative light scattering detection (UHPLC-ELSD) for analysing saccharide contents of various onion ( Allium cepa L.) cultivars substantially differing in their FOS pattern. Analyte identity was confirmed by authentic standards and UHPLC-electrospray ionization-high resolution mass spectrometry (UHPLC-ESI-HRMS). A total of 41 saccharides was detected with both methods, including FOS with a DP of up to 20. Specific validation parameters obtained with authentic standards are presented for FOS with a DP of up to 9. Although run times were significantly shorter using the UHPLC method, baseline separation and analytical range of FOS with higher DP were clearly superior using HPAEC-PAD, reaching lower quantification limits (0.12–2.3 mg/L) compared to UHPLC-ELSD (34–68 mg/L). This work provides guidance for method selection when analysing FOS from plant samples.

Alterations of volatiles during accelerated light-induced ageing of pineapple juice were assessed by HS-SPME-GC-MS in a non-targeted profiling analysis over a 16-week period. Multivariate statistics permitted to reveal substantial chemical markers generally describing the effect of light storage. Volatiles generated comprised phenylpropenes, carbonyls, 2-methylthiophene, toluene, and furfural, while concentrations of methyl and ethyl esters, terpenes, and furanones decreased. In addition, the qualitative composition of phenolic compounds and glycoside-bound volatiles in selected samples was characterized by HPLC-DAD-ESI-MSn as well as HR-ESI-MS. The fresh juice contained unique pineapple metabolites such as S-p-coumaryl, S-coniferyl, S-sinapylglutathione, and structurally related derivatives. Among others, the presence of p-coumaroyl, feruloyl, and caffeoylisocitrate as well as three 4-hydroxy-2,5-dimethyl-3(2H)-furanone glycosides in pineapples could be substantiated by the HR-ESI-MS experiment. Mass spectrometric assignments of selected metabolites are presented, and putative linkages between volatiles and their precursors are established.

A method for the simultaneous extraction and quantitation of gallotannins, flavonoids and anacardic acids from pistachio hulls is presented. After screening of various extraction parameters and solvent systems with variable polarity and acidity, a three-fold repeated extraction with methanol/water/formic acid (80/19/1, v/v/v) at a sample-to-solvent ratio of 1/20 (w/v) under probe-sonication was found to be most suitable for extracting ≥95% of the abovementioned phenolics. A newly developed UHPLC-DAD-ELSD method was compared to an HPLC method for compound separation and quantitation. While analyses by UHPLC were 3.7 times faster, the core-shell particle HPLC column used allowed a superior peak resolution, particularly regarding anacardic acids. While phenolic acids were virtually undetectable by ELSD, it may be applicable for the determination of anacardic acids. However, ELSD sensitivity was inferior to that of the DAD used. Furthermore, validation parameters such as signal linearity, detection and quantitation limits, extraction recoveries, intra- and inter-day repeatability are presented. The new method was applied to pistachio hulls of three different varieties. Phenolic contents ranged from 61.2 ± 0.45 to 100 ± 0.48 g/kg dry matter. Among phenolic constituents, anacardic acids prevailed (64.6–80.4% of total phenolics) followed by gallotannins (13.4–21.2%), such as β-glucogallin, gallic acid, and penta-O-galloyl-β- d -glucose, and flavonol glycosides (5.7–16.3%).

Anthocyanins in two Chilean maqui berry (Aristotelia chilensis (Mol.) Stuntz) clones named Luna Nueva and Morena were isolated and characterized by a core-shell column-based HPLC–DAD–ESI/MSn method and 2D–NMR spectroscopy, focusing on the yet not fully elucidated glycosylation pattern of the aglycones. For the first time, 2D–NMR spectroscopic data unambiguously showed that the major maqui anthocyanins were delphinidin 3-O-(2″-O-β-xylopyranosyl-β-glucopyranoside)-5-O-β-glucopyranoside and delphinidin 3-O-β-glucopyranoside-5-O-β-glucopyranoside. Among these pigments, the latter represented the most abundant anthocyanin in Luna Nueva (59% of total anthocyanin content, TAC) and Morena (50% of TAC). TAC was significantly higher in Luna Nueva (14.6 g/kg dry weight, DW) than in Morena (12.8 g/kg DW). In both samples, relative proportions of diglycosylated anthocyanins (84% of TAC) exceeded those of mono-substituted anthocyanins (∼16%). The provided information about the position of glycosylation may be relevant for assessing color stability of maqui anthocyanins in future food applications.

The aim of the present study was to evaluate the applicability of Quillaja saponaria extract (QSE) and Nα-lauroyl-l-arginine ethyl ester (LAE) as antimicrobial wash water additives in fresh-cut lettuce processing. Antibacterial activities of LAE and QSE against selected strains of the foodborne pathogens Salmonella enterica, Bacillus cereus, Staphylococcus aureus, Pseudomonas aeruginosa, and Listeria monocytogenes were examined in vitro. Minimum inhibitory concentrations determined by broth microdilution assay demonstrated that LAE exhibited a strong antimicrobial activity with MICs between 4 and 32 μg/mL against all tested strains, whereas QSE showed a weaker antimicrobial activity with MICs >512 μg/mL. On a pilot-plant scale, the effects of warm water washing at 45 °C for 120 s with and without 40 mg/L QSE or 100 mg/L LAE as well as cold water washing at 4 °C for 120 s with QSE or LAE, respectively, of shredded endive (Cichorium endivia L.) were investigated regarding microbiological and sensory quality as well as physiological properties. Samples were analyzed for headspace O2 and CO2 levels, phenylalanine-ammonia-lyase activity and contents of nitrite and nitrate during nine days of cold storage at 4 °C. By analogy to its antimicrobial effect against the foodborne pathogens in vitro, LAE allowed up to 4 log10 cfu/mL reduction of the microbial load in the washing water of the pilot plant, and might therefore reduce cross-contamination while saving water. The addition of LAE to warm washing water impaired sensory properties of fresh-cut endive during storage, which was predicted by chlorophyll fluorescence imaging analyses. QSE treatment combined with warm water washing best retained sensory appearance throughout our study, being possibly suitable for the production of premium products.

Enzyme inhibitors were studied as adjuvant treatments in the control of litchi pericarp browning by protection against desiccation during reefer transport. Various organic acids (acetic, malic, citric, and oxalic acid) and inorganic salts (NaCl, CaCl2) were investigated for in vitro inhibitory effects on the peroxidases (POD) and phenol oxidases (including laccase) extracted from litchi pericarp. Promising inhibitors were tested on ‘Hong Huey’ litchi fruit for their capability to prevent pericarp browning during cold storage (21 d, 5 °C, 90% relative humidity) with and without foil wrapping. An enzyme assay had been optimized for measuring the in vitro activities of phenol oxidases toward (−)-epicatechin, being the natural phenolic key substrate in litchi. Phenol oxidase activities were chiefly pH-dependent and completely inactivated at pH ≤ 3.5 by the organic acids used for buffering, whereby chelating agents performed best, especially oxalic acid. POD activity was stable over wider pH and ionic strength ranges, with inhibition being maximal (84%) in 0.25 M oxalic acid buffer (pH 3.5). CaCl2 (0.25 mol L−1) decreased POD activity by 68%, while rising doses increased the initial lag phase up to 2.5 min. In contrast to these in vitro enzyme-inhibiting effects, postharvest fruit treatments with these phenol oxidase and peroxidase inhibitors did not improve color retention during cold fruit storage, but proved ineffective or even favored pericarp browning compared to the control fruit. Pericarp color retention was maximal (96–97%) throughout cold storage of fruit in gas-permeable but moisture-retaining foil bags for at least two weeks, whether the fruit had been dipped into cold water (control) or into citrate (25 mmol L−1) solution. Consequently, pericarp color retention only required an intact pericarp at harvest and postharvest protection against desiccation. Preventing water loss through preservation of cell compartmentation thus proved to be crucial and sufficient for the control of enzymatic browning under reefer conditions.