Raspberry (Rubus idaeus L.) wine: Yeast selection, sensory evaluation and instrumental analysis of volatile and other compounds

Volatilomics of Fruit Wines

Volatilomics is a scientific field concerned with the evaluation of volatile compounds in the food matrix and methods for their identification. This review discusses the main groups of compounds that shape the aroma of wines, their origin, precursors, and selected metabolic pathways. The paper classifies fruit wines into several categories, including ciders and apple wines, cherry wines, plum wines, berry wines, citrus wines, and exotic wines. The following article discusses the characteristics of volatiles that shape the aroma of each group of wine and the concentrations at which they occur. It also discusses how the strain and species of yeast and lactic acid bacteria can influence the aroma of fruit wines. The article also covers techniques for evaluating the volatile compound profile of fruit wines, including modern analytical techniques.

Overview of the distinctive characteristics of strawberry, raspberry, and blueberry in berries, berry wines, and berry spirits

Red berries have gained popularity as functional and nutritious food due to their health benefits, leading to increased consumer demand and higher production, totaling over 11,000 ktons for strawberries, raspberries, and blueberries combined in 2021. Nutritionally, strawberries, raspberries, and blueberries present high levels of vitamin C (9.7-58.8 mg/100 g dry weight [dw]), folates (6-24 µg/100 g dw), and minerals (96-228 mg/100 g dw). Due to their perishable nature, producers have utilized alcoholic fermentation to extend their shelf life, not only increasing the lifespan of red berries but also attracting consumers through the production of novel beverages. Strawberry, blueberry, and raspberry wines possess low alcohol (5.5-11.1% v/v), high acidity (3.2-17.6 g/L), and interesting bioactive molecules such as phenolic compounds, carotenoids, polysaccharides, and melatonin. Distillation holds tremendous potential for reducing food waste by creating red berry spirits of exceptional quality. Although research on red berry spirits is still in the early stages, future studies should focus on their production and characterization. By incorporating these factors, the production chain would become more sustainable, profitable, and efficient by reducing food waste, capitalizing on consumer acceptance, and leveraging the natural health-promoting characteristics of these products. Therefore, this review aims to provide a comprehensive overview of the characteristics of strawberry, blueberry, and red raspberry in berries, wines, and spirits, with a focus on their chemical composition and production methods.

Effect of high-voltage electrospray on the inactivation, induced damage and growth of microorganisms and flavour components of honey raspberry wine

Electrospray (ES) is a new non-thermal processing technology for pasteurising liquid foods. This study aimed to investigate the effects of ES on the cell structure and function of Saccharomyces cerevisiae, Escherichia coli and Staphylococcus aureus and then compare the effects of ES and heat treatment (HT) on microbial inactivation and flavour composition in honey raspberry wine. First, we found that the inactivation effect of ES treatment on the three microorganisms was significantly influenced by the voltage intensity. The degree of damage to the cellular structures and functions of the three microorganisms increased with increasing voltage. Second, the environment in which the microorganisms were present significantly influenced the ES pasteurisation effect. Pasteurisation by ES was better when the three microorganisms were in honey raspberry wine than in saline. Finally, the total number of colonies in honey raspberry wine was reduced from 4.50 to 2.03 log colony forming units/mL after ES treatment, and the wine had good stability during storage (84 days at 4 °C). In the honey raspberry wine, the contents of the main flavour substances (ketones and esters) did not change significantly after ES treatment, but HT decreased the content of esters and ketones by 13.5 % and 75.4 %, respectively.

Chemical and Sensory Characteristics of Fruit Juice and Fruit Fermented Beverages and Their Consumer Acceptance

Recent social, economic, and technological evolutions have impacted consumption habits. The new consumer is more rational, more connected and demanding with products, more concerned with the management of the family budget, with the health, origin, and sustainability of food. The food industry over the last few years has shown remarkable technological and scientific evolution, with an impact on the development and innovation of new products using non-thermal processing. Non-thermal processing technologies involve methods by which fruit juices receive microbiological inactivation and enzymatic denaturation with or without the direct application of low heat, thereby lessening the adverse effects on the nutritional, bioactive, and flavor compounds of the treated fruit juices, extending their shelf-life. The recognition of the nutritional and protective values of fruit juices and fermented fruit beverages is evident and is attributed to the presence of different bioactive compounds, protecting against chronic and metabolic diseases. Fermentation maintains the fruit's safety, nutrition, and shelf life and the development of new products. This review aims to summarize the chemical and sensory characteristics of fruit juices and fermented fruit drinks, the fermentation process, its benefits, and its effects.

Comparison of volatile compounds and sensory profiles of alcoholic black currant (Ribes nigrum) beverages produced with Saccharomyces, Torulaspora, and Metschnikowia yeasts

Black currants (Ribes nigrum) were fermented with Saccharomyces and non-Saccharomyces yeasts without added sugar to yield low-ethanol-content beverages. The effects of yeasts on the volatile compounds and sensory characteristics were analysed by HS-SPME-GC-MS, GC-O, and generic descriptive analysis. Ninety-eight volatile compounds were identified from the black currant juice and fermented beverages. Significant increases in the contents of esters (131 %), higher alcohols (391 %), and fatty acids (not present in juice sample) compared to initial juice were observed depending on the yeasts used. GC-O analysis revealed the higher impact of esters on the sensory properties of Saccharomyces bayanus-fermented beverage compared to the Torulaspora delbrueckii-fermented beverage. In the sensory evaluation, non-Saccharomyces yeasts resulted in a higher 'black currant odour'. However, all beverages were intensely sour, which can be a significant challenge in the development of alcoholic berry beverages.

Effect of the inoculation strategies of selected Metschnikowia agaves and Saccharomyces cerevisiae on the volatile profile of pineapple wine in mixed fermentation

To investigate the effects of inoculation ratio, concentration, and sequence of selected Metschnikowia agaves P3-3 and commercial Saccharomyces cerevisiae D254 on the volatiles of pineapple wine in mixed fermentation, the growth and fermentation ability of two yeast strains were monitored, and the physicochemical characteristics (including reducing sugar, total acidity, volatile acidity, and ethanol content) and volatile profile of pineapple wines produced by different inoculation strategies were analysed using chemical method and headspace-solid phase microextraction with gas chromatography-mass spectrometry (HS-SPME-GCMS), respectively. Results indicate that although the proliferation of M. agaves P3-3 was repressed by S. cerevisiae D254, changes in inoculation methods influenced yeast-yeast interactions and modulated the physicochemical properties and volatile profile of pineapple wine. Inoculation sequence and concentration of two strains were more important to volatile profile of pineapple wine than inoculation ratio. Simultaneous inoculations with 1 × 10⁷ CFU/mL M. agaves P3-3 and sequential inoculations increased the total acidity level, but their volatile acidity was lower than that with 5 × 10⁶ CFU/mL M. agaves P3-3. Simultaneous inoculations with 5 × 10⁶ CFU/mL M. agaves P3-3 retained more types of variety volatiles. However, the appropriate increase in the inoculation concentration of the cells and sequential inoculation increased the fermentative volatiles, especially ester levels.

SUPPLEMENTARY INFORMATION

The online version of this article (10.1007/s13197-021-05019-2) contains supplementary material, which is available to authorized users.

Evaluation of Probiotic Properties of Pediococcus acidilactici M76 Producing Functional Exopolysaccharides and Its Lactic Acid Fermentation of Black Raspberry Extract

This study aimed to determine the probiotic potential of Pediococcus acidilactici M76 (PA-M76) for lactic acid fermentation of black raspberry extract (BRE). PA-M76 showed outstanding probiotic properties with high tolerance in acidic GIT environments, broad antimicrobial activity, and high adhesion capability in the intestinal tract of Caenorhabditis elegans. PA-M76 treatment resulted in significant increases of pro-inflammatory cytokine mRNA expression in macrophages, indicating that PA-M76 elicits an effective immune response. When PA-M76 was used for lactic acid fermentation of BRE, an EPS yield of 1.62 g/L was obtained under optimal conditions. Lactic acid fermentation of BRE by PA-M76 did not significantly affect the total anthocyanin and flavonoid content, except for a significant increase in total polyphenol content compared to non-fermented BRE (NfBRE). However, fBRE exhibited increased DPPH radical scavenging activity, linoleic acid peroxidation inhibition rate, and ABTS scavenging activity of fBRE compared to NfBRE. Among the 28 compounds identified in the GC-MS analysis, esters were present as the major groups. The total concentration of volatile compounds was higher in fBRE than that in NfBRE. However, the undesirable flavor of terpenes decreased. PA-M76 might be useful for preparing functionally enhanced fermented beverages with a higher antioxidant activity of EPS and enhanced flavors.

Biotechnological Processes in Fruit Vinegar Production

The production of fruit vinegars as a way of making use of fruit by-products is an option widely used by the food industry, since surplus or second quality fruit can be used without compromising the quality of the final product. The acetic nature of vinegars and its subsequent impact on the organoleptic properties of the final product allows almost any type of fruit to be used for its elaboration. A growing number of scientific research studies are being carried out on this matrix, and they are revealing the importance of controlling the processes involved in vinegar elaboration. Thus, in this review, we will deal with the incidence of technological and biotechnological processes on the elaboration of fruit vinegars other than grapes. The preparation and production of the juice for the elaboration of the vinegar by means of different procedures is an essential step for the final quality of the product, among which crushing or pressing are the most employed. The different conditions and processing methods of both alcoholic and acetic fermentation also affect significantly the final characteristics of the vinegar produced. For the alcoholic fermentation, the choice between spontaneous or inoculated procedure, together with the microorganisms present in the process, have special relevance. For the acetic fermentation, the type of acetification system employed (surface or submerged) is one of the most influential factors for the final physicochemical properties of fruit vinegars. Some promising research lines regarding fruit vinegar production are the use of commercial initiators to start the acetic fermentation, the use of thermotolerant bacteria that would allow acetic fermentation to be carried out at higher temperatures, or the use of innovative technologies such as high hydrostatic pressure, ultrasound, microwaves, pulsed electric fields, and so on, to obtain high-quality fruit vinegars.

Characterization of Phytochemicals in Berry Fruit Wines Analyzed by Liquid Chromatography Coupled to Photodiode-Array Detection and Electrospray Ionization/Ion Trap Mass Spectrometry (LC-DAD-ESI-MSn) and Their Antioxidant and Antimicrobial Activity

Fruits are a valuable source of phytochemicals. However, there is little detailed information about the compounds contained in fruit wines. In this study, wines from six different berries were analyzed using HPLC-DAD-ESI-MSⁿ. About 150 compounds were identified, including anthocyanins (34), hydroxycinnamic acids (12) and flavonols (36). Some of the compounds were identified for the first time in berry wines. The blackberry wines were found to contain the largest number of bioactive compounds (59). Elderberry wines where the richest source of polyphenols (over 1000 mg/L) and contained the largest amounts of all of the analyzed groups of compounds (hydroxycinnamic acids, anthocyanins and flavonols). The lowest concentration of polyphenols was observed in the wines made from cranberries and bilberries (less than 500 mg/L). The antioxidant activity was determined in relation to ABTS⁺, DPPH, and FRAP. The highest values were observed in the blackberry wines, and the lowest for the cranberry wines. The wines were analyzed to test their antimicrobial activity. Five of the six wines (with the exception of elderberry wine) inhibited Bacillus cereus growth and two (blackberry and cranberry wines) were active against Listeria monocytogenes.

Effect of Saccharomyces cerevisiae, Torulaspora delbrueckii and malolactic fermentation on fermentation kinetics and sensory property of black raspberry wines

Alcoholic fermentation (AF) and malolactic fermentation (MLF) both have significant influence on the production of black raspberry wine. In this study, three microbes associated with AF and MLF including S. cerevisiae, T. delbrueckii and O. oeni were used to investigate their combined effect on basic compositional, volatile and sensory property of black raspberry wine, and four fermentation trials including single S. cerevisiae inoculation plus spontaneous MLF (BSU) and controlled MLF with O. oeni (BSO), sequential culture of T. delbrueckii and S. cerevisiae plus spontaneous MLF (BTSU) and controlled MLF (BTSO) were tested and compared. Fermentation results showed MLF in BSU, BSO and BTSO were successful, with respective period of 40, 25 and 23 days, whereas a stuck MLF occurred in BTSU. Volatile compounds were determined by HS-GC-IMS method, with a total of 45 aromas identified. BTSO was distinguished by a significant higher signal intensity of many fruity esters and a lower production of several alcohols and terpenes, which was in agreement with its perception result of strong 'fruity' and slight note of 'solvent' and 'herbaceous' during quantitative descriptive analysis. On the contrary, BSU was found to reinforce the synthesis of most detected volatiles, resulting in the enhancement of both beneficial and off-flavour compounds, therefore scoring lower in the 'global aroma' descriptor. Principal component analysis showed BSU and BSO were similar in the volatile composition, whereas BTSO was quite different. Overall, BTSO had greater potential to be used in the production of black raspberry wine.

Production and characterization of a new distillate obtained from fermentation of wet processing coffee by-products

Coffee is one of the most important commodities worldwide. The industrial processing of coffee cherries generates a considerable volume of by-products such as wastewater, coffee pulp, mucilage, and husk. These by-products have sugars and nutrients that can be converted into value-added products via microbial action. In this study, for the first time, we evaluated the potential of coffee pulp and coffee wastewater as substrate for alcoholic fermentation produce a distilled beverage. The must composed by dry or wet coffee pulp and coffee wastewater added of commercial sucrose or sugarcane molasses was fermented by S. cerevisiae. After a screening step, a larger fermentation was carried out with the wet pulp added of sucrose due to its higher alcoholic fermentation efficiency. The distilled beverage contained 38% (v/v) ethanol and 0.2 g/L of acetic acid. The contaminants furfural, hydroxymethylfurfural and ethyl carbamate were below detection level. Among the 48 volatile compounds detected, the majority (21) were ethyl esters usually associated with floral and sweet aromas. Ethyl decanoate (996.88 µg/L) and ethyl dodecanoate (1088.09 µg/L) were the most abundant esters. Coffee spirit presented taste acceptance of 80% and sugarcane spirit, 70%. The tasters indicated an aroma acceptance of 86% for the coffee spirit and 78% for the sugarcane spirit. The results of this work demonstrate the potential for using coffee by-products to produce a good quality distilled beverage. Considering our results, especially sensorial analysis, we can infer that the produced coffee beverage represents a new alternative for adding value to the coffee production chain.

Improved flavor profiles of red pitaya (Hylocereus lemairei) wine by controlling the inoculations of Saccharomyces bayanus and Metschnikowia agaves and the fermentation temperature

The effects of the inoculation method of Saccharomyces bayanus BV818 and non-Saccharomyces yeast Metschnikowia agaves P3-3 and the fermentation temperature on the volatile profiles of red pitaya wine were investigated in the present study. Although the growth of P3-3 was inhibited by BV818 in the mixed inoculations, simultaneous and sequential inoculations promoted the production of seven volatiles, including higher alcohols (propan-1-ol, 3-methyl-1-butanol and phenethyl alcohol), esters (ethyl decanoate and diethyl succinate), acid (2-ethylhexanoic acid), and ketone (acetoin). Sequential inoculation produced the largest total content of volatile compounds and exhibited the best in the global aroma. The red pitaya wine produced in different inoculations can be separated by its main volatile components. Furthermore, the highest total content was yielded at 25 °C for alcohols and at 21 °C for esters and acids. Within an experimental range of 17 °C to 29 °C, the contents of benzaldehyde and acetoin decreased with the increase in temperature, whereas the change in 4-ethyl-2-methoxyphenol content was the opposite. The similarly high total contents of volatiles and global aroma score were yielded via sequential inoculation at 21 °C and 25 °C. Therefore, the desired red pitaya wine can be effectively produced by modulating the inoculation method and fermentation temperature.

Biosynthesis of Benzylic Derivatives in the Fermentation Broth of the Edible Mushroom, Ischnoderma resinosum

Employing isotope incubation studies, the biosynthetic pathway leading to a series of benzylic derivatives was elucidated in the fermentation broth of the edible mushroom Ischnoderma resinosum (P. Karst). Twenty-six hydroxy- and methoxy- benzylic derivatives were screened by gas chromatography-mass spectrometry (GC-MS) of which 13 were detected in the culture media. Results from the isotope incubation studies showed the transformation of both benzyl alcohol and benzoic acid into benzaldehyde. Benzaldehyde was then converted into 4-methoxybenzaldehyde via hydroxylation and subsequent methylation of the 4-C position. The resulting 4-methoxybenzaldehyde was then hydroxylated in the 3-C position followed by methylation into 3,4-dimethoxybenzaldehyde. Based on these findings, a novel metabolic scheme for the biosynthesis of benzylic derivatives in I. resinosum was proposed. The knowledge of the biosynthetic pathway was utilized to produce 4-hydroxy-3-methoxybenzaldehyde (vanillin) from 4-hydroxy-3-methoxybenzoic acid (vanillic acid). This is the first report to elucidate the biosynthetic pathway of benzyl derivatives and production of vanillin from I. resinosum.

Identification of Key Aroma Compounds in Cranberry Juices as Influenced by Vinification

This study aimed to identify the key aroma-active volatiles in cranberry wines through three vinification methods (White, Red and Thermo) using GC-MS/O to identify the important aroma compounds. A total of 70 compounds were detected, with 67 in wines and 61 in juices. The esters was the most diversified class, while alcohols and acids were the most abundant, especially 3-methylbutanol, methylbutyric acid, and benzoic acid. The volatile profiles of cranberry wines are distinctive from their source juices. Most alcohols, esters, and acids are fermentation-derived, while terpenes, phenols, aldehydes and ketones are varietal. The Red vinification retained the most varietal volatiles from the must, while the White and Thermo vinifications produced more volatiles during fermentation. Thermovinification reduced the yield of benzoic acid and its derivatives after fermentation. Olfactory analysis identified 47 aroma-active compounds, among which 41 were considered as the major aroma contributors (ethyl benzoate had the highest modified detection frequency).

The Influence of Vinification Methods and Cultivars on the Volatile and Phenolic Profiles of Fermented Alcoholic Beverages from Cranberry

This study investigated the effects of vinification techniques and cultivars (Stevens, Pilgrim and Bergman) on cranberry wine quality. Three winemaking technologies were conducted to prepare cranberry musts before fermentation, including traditional red and white vinifications (Red and White), and thermovinification (Thermo). In wine products, proanthocyanins (PACs) and anthocyanins (ANCs) are dominant in phenolics, while esters and alcohols are prevalent in volatiles, with phenylethyl alcohol, β-damascenone, benzyl alcohol, etc. as the main contributors to the aroma. The phenolic compositions of wines were in the same pattern with cultivars: the Stevens and Bergman wines contained the highest amount of ANCs and PACs, respectively, while the Pilgrim wines had the lowest total phenolic contents (TPC), and antioxidant capacities (AOC). Nevertheless, products from Pilgrim cultivar had a distinctive pattern of volatiles compared to Stevens and Bergman, especially for aromatic compounds. Considering vinification methods, Thermo demonstrated advantages on correlations with both phenolic and volatile (polymeric and monomeric) compositions.

Evaluation of the volatile profile of wax apple (Syzygium samarangense) wines fermented with different commercial Saccharomyces cerevisiae strains

The effect of four commercial Saccharomyces cerevisiae strains (D254, VIC, BV818, and RV100) on the volatile profile of wax apple (Syzygium samarangense) wine was investigated in this study. Alcohols and esters were the most two abundant groups of identified volatiles in wax apple wines. However, different S. cerevisiae strains possess various capacities in releasing/synthesizing volatiles with varied mRNA levels of genes involved in volatiles metabolism during wax apple wine fermentation. VIC, which yielded the highest total concentration of volatiles and largest number of volatiles with odor activity value (OAV) > 1, could be used as a starter culture to produce wax apple wine characterized with intense aroma. D254 and RV100, which produced the greatest variety of volatiles and scored the highest in global aroma, respectively, could be used to enhance the wine complexity. Four wax apple wines could be differentiated by their main volatile compounds.

Key Odorants from the Fermentation Broth of the Edible Mushroom Ischnoderma resinosum

Eighteen odorants were identified by applying aroma extract dilution analysis in the liquid fermentation broth of the edible mushroom Ischnoderma resinosum (P. Karst). Eight compounds with flavor dilution factors ≥16 were quantitated in a 16-day sample using stable isotope dilution assays. Odor activity values (OAV) revealed anise-smelling 4-methoxybenzaldehyde (OAV; 1639), vanilla-smelling 3,4-dimethoxybenzaldehyde (OAV; 51), and cherry-smelling benzaldehyde (OAV; 14) as key contributors to the pleasant "candy-like" odor of the fermentation broth. Odor simulation experiments revealed a mixture of five compounds in their natural concentrations mimicked the odor of a 16-day-old fermentation broth. A 30-day time course study was conducted to monitor the production of three odorants in the fungal fermentation broth, where it was revealed that both 3,4-dimethoxybenzaldehyde (10.7 ± 1.0 mg/kg) and benzaldehyde (4.5 ± 0.1 mg/kg) peaked on day 16, whereas 4-methoxybenzaldehyde peaked on day 24 (104.9 ± 4.9 mg/kg).

Characterization of Odor-Active Volatiles in Hawthorn Puree Using Thermal Desorption System Coupled to Gas Chromatography-Mass Spectrometry-Olfactometry and GC-Flame Photometric Detector

The volatile compounds in hawthorn puree obtained from three cultivars (Y1, Crataegus pinnatifida Bunge cv. "Waibahong", Y2, Crataegus pinnatifida Bunge cv. "Damianqiu", and Y3, Crataegus pinnatifida Bunge cv. "Dajinxing") were analyzed by the thermal desorption system coupled to gas chromatography-mass spectrometry-olfactometry and GC-flame photometric detector. In the samples of Y1, Y2, and Y3, 40, 42, and 42 odor-active compounds were, respectively, identified by olfactometry. Methyl 2-methylbutanoate, methyl hexanoate, hexyl isobutanoate, methional, heptanal, and ( Z)-3-hexenyl acetate contributed largely to the characteristic aroma of the three samples. Additionally, the odor activity value (OAV) was used to determine the main compounds and 3-mercaptohexyl acetate (OAV: 10-18), 3-mercapto-2-methylpentanal (OAV: 4-7), methyl 2-methylbutanoate (OAV: 9-21), methyl hexanoate (OAV: 8-16), and 2-pentyl acetate (OAV: 5-12) were considered as the important contributors to the aroma of hawthorn samples.

Evaluation of different Saccharomyces cerevisiae strains on the profile of volatile compounds in pineapple wine

Yeast strain plays a central role in the formation of aroma and flavour of fruit wine. The effect of four commercial Saccharomyces cerevisiae strains (D254, VIC, BV818 and CECA) on volatile compounds of fermented pineapple (Ananas comosus L. Merr.) juice was investigated. Alcohols and esters were the most abundant groups in terms of the amounts of identified volatiles in four pineapple wines, followed by acids and sulphur compounds. Different S. cerevisiae strains possess various capacities to release or synthesize volatiles during pineapple wine fermentation. For global aroma, strain D254 yielded the highest total number and concentration of volatiles and could be used as a starter culture for the making of intense pineapple wine. Strain BV818 produced wine with the highest amounts of volatiles with OAVs > 1 and scored the highest in global aroma. Thus, BV818 might be the appropriate strain that could impart characteristic aromas and enhance wine complexity. The relative content of esters formed by strain VIC was higher than that yielded by the other strains. Strain CECA produced the highest relative contents of alcohols, aldehydes and ketones. However, VIC and CECA were not ideal starter cultures because of their low sense scores. This study provided a foundation for the production of pineapple wine with the desired flavour profile.

Characterization of the Major Odor-Active Compounds in Dry Jujube Cultivars by Application of Gas Chromatography-Olfactometry and Odor Activity Value

The volatile compounds of jujube ( Ziziphus jujube Mill.) puree obtained from three cultivars, 'Jinsixiaozao' (Y1), 'Youzao' (Y2), and 'Yuzao' (Y3), were analyzed by gas chromatography-olfactometry (GC-O), gas chromatography-mass spectrometry, gas chromatography-flame photometric detection, and a nitrogen phosphorus detector. The results showed that a total of 37, 37, and 35 odor-active compounds were identified by GC-O in samples of Y1, Y2, and Y3, respectively. In addition, the odor activity value (OAV) was used to determine the important compounds. The results demonstrated that hexanal (OAV of 39-85), ( E)-2-octenal (OAV of 32-70), β-damascenone (OAV of 14-49), ethyl hexanoate (OAV of 22-39), 3-mercaptohexyl acetate (OAV of 17-24), and 2,5-dimethylpyrazine (OAV of 17-22) were key odor-active compounds. It is of great significance to develop high-grade jujube food by determining key odor-active compounds. Furthermore, four volatiles (hexanal, 1-octen-3-ol, 3-mercapohexyl acetate, and benzaldehyde) reduced the overall threshold value by 2.36, 1.01, 1.34, and 1.19, respectively.

Comparing conventional Descriptive Analysis and Napping®-UFP against physiochemical measurements: a case study using apples

BACKGROUND

The extensive time and cost associated with conventional sensory profiling methods has spurred sensory researchers to develop rapid method alternatives, such as Napping® with Ultra-Flash Profiling (UFP). Napping®-UFP generates sensory maps by requiring untrained panellists to separate samples based on perceived sensory similarities. Evaluations of this method have been restrained to manufactured/formulated food models, and predominantly structured on comparisons against the conventional descriptive method. The present study aims to extend the validation of Napping®-UFP (N = 72) to natural biological products; and to evaluate this method against Descriptive Analysis (DA; N = 8) with physiochemical measurements as an additional evaluative criterion.

RESULTS

The results revealed that sample configurations generated by DA and Napping®-UFP were not significantly correlated (RV = 0.425, P = 0.077); however, they were both correlated with the product map generated based on the instrumental measures (P < 0.05). The finding also noted that sample characterisations from DA and Napping®-UFP were driven by different sensory attributes, indicating potential structural differences between these two methods in configuring samples.

CONCLUSIONS

Overall, these findings lent support for the extended use of Napping®-UFP for evaluations of natural biological products. Although DA was shown to be a better method for establishing sensory-instrumental relationships, Napping®-UFP exhibited strengths in generating informative sample configurations based on holistic perception of products. © 2017 Society of Chemical Industry.

Probiotic potential of yeasts isolated from pineapple and their use in the elaboration of potentially functional fermented beverages

Pineapple (Ananas comosus (L.) Merril) is a tropical fruit rich in nutrients characterized by a pleasant taste and widely consumed in several countries. It is used to produce juice, jams and wine. In this work, 150 yeasts isolates were obtained from peel (18) and spontaneously fermented pineapple pulp (132). The probiotic potential of 50 isolates was studied. Survival at pH 2.0, pepsin 3.0 g/L, and tolerance of bile salts (0.1 and 1% (w/v) were determined as indicators of survival potential of the isolates during the passage through the human gastrointestinal tract in simulated conditions. The selected isolates were also evaluated for their resistance to 6 antibiotics, antimicrobial activity against 6 pathogenic bacteria and autoaggregation and hydrophobicity properties. Five of them survived to gastrointestinal conditions, showed antibiotic resistance and autoaggregation properties. They were identified by MALDI-TOF MS and sequencing of ITS region as Candida lusitaniae (3) and Meyerozyma caribbica (2). Among these isolates, M. caribbica 9 D was evaluated in the production of a fermented pineapple beverage. The Saccharomyces cerevisiae var. boulardii was used as control, due to the fact that it is the only commercially available probiotic yeast. With M. caribbica inoculum, the beverage produced showed higher concentrations of residual glucose (24.19 g/L) and fructose (8.67 g/L), lower concentration of acetic acid (0.22 g/L); higher total phenolic compounds (196.93 mg/L), catechin (155.56 mg/L), chlorogenic acid (3.64 mg/L), vanillin (0.18 mg/L) and ferulic acid (33.2 mg/L). It was observed that M. caribbica population remained stable during refrigerated storage with cell counts greater than 7.00 log CFU/mL over 21 days. Compared to beverage produced with S. cerevisiae var. boulardii, the one produced with M. caribbica presented greater acceptance in the sensorial analysis for taste, aroma and general acceptance. The fermented pineapple beverage prepared with M. caribbica proved to be a good alternative in development of a potential probiotic beverage with different sensory and nutritional properties.

The Effects of Pre-Fermentative Addition of Oenological Tannins on Wine Components and Sensorial Qualities of Red Wine

Today in the wine industry, oenological tannins are widely used to improve wine quality and prevent oxidation in wine aging. With the development of tannin products, new oenological tannins are developed with many specific functions, such as modifying antioxidant effect, colour stabilization and aroma modifications. The aim of this work is to investigate effects of pre-fermentative addition of oenological tannins on wine colour, anthocyanins, volatile compounds and sensorial properties. In this case, Syrah juice was extracted with classic flash thermovinification from fresh must in order to release more colour and tannins. Three types of oenological tannins, which are, respectively, derived from grape skin, seed (Vitis vinifera) and French oak (Quercus robur and Querrus petraea), were selected to carry out the experiments with seven treatments. Results indicated that tannin treatments significantly improved wine aroma complexity and sensorial properties. However, the concentration of some stable pigments such as Vitisin A, Vitisin A-Ac and Vitisin B was negatively affected by tannin additions. Nevertheless, by means of cluster analysis and principal component analysis, it was observed that higher alcohols were significantly promoted by grape seed tannin while most anthocyanins can be improved by addition of grape tannins. In conclusion, low amount of oenological tannin derived from grape seed is a promising method to be applied especially for young red wine making.

Hibiscus sabdariffa (Roselle) Extracts and Wine: Phytochemical Profile, Physicochemical Properties, and Carbohydrase Inhibition

Three varieties of Hibiscus sabdariffa were analyzed for their phytochemical content and inhibitory potential on carbohydrate-digesting enzymes as a basis for selecting a variety for wine production. The dark red variety was chosen as it was highest in phenolic content and an aqueous extract partially inhibited α-glucosidase (maltase), with delphinidin 3-O-sambubioside, cyanidin 3-O-sambubioside, and 3-O-caffeoylquinic acid accounting for 65% of this activity. None of the varieties significantly inhibited α-amylase. Regarding Hibiscus sabdariffa wine, the effect of fermentation temperature (20 and 30 °C) on the physicochemical, phytochemical, and aroma composition was monitored over 40 days. The main change in phytochemical composition observed was the hydrolysis of 3-O-caffeolquinic acid and the concomitant increase of caffeic acid irrespective of fermentation temperature. Wine fermented at 20 °C was slightly more active for α-glucosidase inhibition with more fruity aromas (ethyl octanoate), but there were more flowery notes (2-phenylethanol) at 30 °C.

Characterization of the Key Aroma Volatile Compounds in Cranberry (Vaccinium macrocarpon Ait.) Using Gas Chromatography-Olfactometry (GC-O) and Odor Activity Value (OAV)

The volatile compounds of cranberries obtained from four cultivars (Early Black, Y1; Howes, Y2; Searles, Y3; and McFarlin, Y4) were analyzed by gas chromatography-olfactometry (GC-O), gas chromatography-mass spectrometry (GC-MS), and GC-flame photometric detection (FPD). The result presented that a total of thirty-three, thirty-four, thirty-four, and thirty-six odor-active compounds were identified by GC-O in the Y1, Y2, Y3, and Y4, respectively. In addition, twenty-two, twenty-two, thirty, and twenty-seven quantified compounds were demonstrated as important odorants according to odor activity values (OAVs > 1). Among these compounds, hexanal (OAV: 27-60), pentanal (OAV: 31-51), (E)-2-heptenal (OAV: 17-66), (E)-2-hexenal (OAV: 18-63), (E)-2-octenal (OAV: 10-28), (E)-2-nonenal (OAV: 8-77), ethyl 2-methylbutyrate (OAV: 10-33), β-ionone (OAV: 8-73), 2-methylbutyric acid (OAV: 18-37), and octanal (OAV: 4-24) contributed greatly to the aroma of cranberry. Partial least-squares regression (PLSR) was used to process the mean data accumulated from sensory evaluation by the panelists, odor-active aroma compounds (OAVs > 1), and samples. Sample Y3 was highly correlated with the sensory descriptors "floral" and "fruity". Sample Y4 was greatly related to the sensory descriptors "mellow" and "green and grass". Finally, an aroma reconstitution (Model A) was prepared by mixing the odor-active aroma compounds (OAVs > 1) based on their measured concentrations in the Y1 sample, indicating that the aroma profile of the reconstitution was pretty similar to that of the original sample.

Sugar cane spirit (cachaça): Effects of mixed inoculum of yeasts on the sensory and chemical characteristics

The main goal of this study was to produce cachaça using a mixed inoculum of Saccharomyces cerevisiae and Meyerozyma caribbica and characterize the produced beverage using HPLC, GC-FID, GC-MS and sensorial analysis. Additionally, the use of MALDI-TOF as a tool to characterize and monitor pure and mixed inocula fermenting sugar cane juice was also evaluated. Vat fermentations were carried out for three consecutive batches using autoclaved 16°Brix sugar cane juice fermented by a mixed inoculum of M. caribbica 10⁷ cells/mL and S. cerevisiae 10⁸ cells/mL. The cachaça produced by the mixed culture of M. caribbica and S. cerevisiae showed the highest concentration of volatile compounds associated with good sensory descriptors such as ethyl hexanoate (114.11μg/L), 2-phenylethyl acetate (2.77μg/L), a-terpineol (0.45μg/L), b-citronellol (2.47μg/L), and geraniol (0.24μg/L). This beverage consequently showed greater acceptance in the sensorial analysis for taste and aroma, especially by younger panelists. The feasibility of MALDI-TOF use under studied conditions was demonstrated by the comparison of the results obtained from yeast cultivation in YPD broth, YPD agar and sugar cane juice, showing that there was no interference of sugar cane juice in protein profile. The results obtained from MALDI-TOF analysis showed that the protein extraction directly from sugar cane juice under fermentation, without the traditional plating step, allowed the distinction between mixed and pure inocula even under different M. caribbica populations and Brix degrees.

Production of Volatile and Sulfur Compounds by 10 Saccharomyces cerevisiae Strains Inoculated in Trebbiano Must

In wines, the presence of sulfur compounds is the resulting of several contributions among which yeast metabolism. The characterization of the starter Saccharomyces cerevisiae needs to be performed also taking into account this ability even if evaluated together with the overall metabolic profile. In this perspective, principal aim of this experimental research was the evaluation of the volatile profiles, throughout GC/MS technique coupled with solid phase micro extraction, of wines obtained throughout the fermentation of 10 strains of S. cerevisiae. In addition, the production of sulfur compounds was further evaluated by using a gas-chromatograph coupled with a Flame Photometric Detector. Specifically, the 10 strains were inoculated in Trebbiano musts and the fermentations were monitored for 19 days. In the produced wines, volatile and sulfur compounds as well as amino acid concentrations were investigated. Also the physico-chemical characteristics of the wines and their electronic nose profiles were evaluated.