Kombucha is a black tea‐based, non‐alcoholic beverage fermented by yeast and bacteria are known for its refreshing scent and taste and presents biological characteristics, namely antioxidant, ...antimicrobial and anti‐inflammatory activity. The present study compared traditional kombucha prepared with black tea and green tea to kombuchas produced with several alternative substrates, including white tea, chrysanthemum, honeysuckle, and mint infusions. Throughout the fermentation process, liquid and gas chromatography analyzed sugars, ethanol, organic acids, and volatile compounds. Sugar consumption was substrate‐dependent, with mint kombucha having the highest amount of residual sugar and honeysuckle having the lowest. Forty‐six volatile organic compounds were detected, including alcohols, esters, acids, aldehydes, ketones, and other compounds. Twenty‐two compounds were produced during the fermentation and identified in all kombuchas; some of these compounds represented fruity and floral aromas. Another 24 compounds were substrate specific. Notably, the herb‐based kombuchas (chrysanthemum, honeysuckle, and mint) contained several compounds absent in the tea‐based kombuchas and are associated with minty, cooling, and refreshing aromas. Mint and green tea kombucha attained the highest and lowest overall sensorial acceptance ratings, respectively. This study demonstrated herbal substrates' suitability to prepare kombucha gastronomically with volatile compound and flavor profiles distinct from tea‐based kombuchas.
Practical Application
The kombucha beverage is a low‐caloric functional drink that is increasingly popular around the world. While it is traditionally produced with black or green tea, this paper explores its production based on other herbal and floral infusions. The kombucha analogs presented in this paper can provide consumers with healthy alternatives for sugary soft drinks while also offering a broader range of flavors.
The intensive efforts to control the “witches' broom” fungus in Brazil have included research on resistant and more productive cocoa cultivars, but the impact of these crosses on cocoa fermentation ...is not known. To understand the effects of breeding on cocoa fermentation, this work investigated the microbes and chemical compounds present during the fermentation of three highly productive hybrids (PH 9, PH 15 and PH 16). The microbial species present during the fermentation process were similar in all three hybrids, but the populations of lactic acid, acetic acid, and mesophilic aerobic bacteria and yeast in the PH 9 hybrid fermentations were greater than those in PH 15 and PH 16. Lactobacillus fermentum, Lactobacillus casei and Lactobacillus rhamnosus were the predominant species in all hybrid cocoa fermentations. However, the profile of the bacterial community detected by PCR-DGGE was more complex in the PH 9 fermentation. The yeast Saccharomyces cerevisiae was predominant in the all fermentations, followed by Hanseniaspora uvarum and the genus Pichia. A similar profile of substrate consumption (glucose, sucrose, fructose and citric acid) and kinetics of major metabolites (ethanol, acetic acid and lactic acid) was also observed, but the PH 16 hybrid presented the highest concentrations of sugars, acids and alcohols.
•Fermentation of three highly productive cocoa hybrids was investigated.•PH 16 cocoa hybrid presented the highest concentrations of sugars, acids and alcohols.•Bacterial community detected by PCR-DGGE was more complex in the PH 9 fermentation.fermentation.
Cereal-based fermented beverages are non-dairy products which are considered possible carriers for probiotic strains and alternatives for use by vegans and lactose-intolerant consumers. In the ...present work, the commercial probiotic, Lactobacillus paracasei LBC-81, was used singly and in co-culture with potential probiotic yeasts, Saccharomyces cerevisiae CCMA 0731, S. cerevisiae CCMA 0732, and Pichia kluyveri CCMA 0615, to ferment a maize-based substrate. All tested strains showed viability higher than 6 log CFU/mL, as recommended for food probiotic products, except for the yeast P. kluyveri which decreased during fermentation and storage time. A reduction in pH value, from approximately 7 to 4, was observed. This decrease was due organic acid production, which did not affect the microbial viability. Lactic and acetic acids were the main organic acids produced during fermentation, and they decreased over 28 days of storage (<0.5 and 0.1 g/L for lactic and acetic acids, respectively). Ethanol was detected in the S. cerevisiae assays; however, the content was <5 g/L in a non-alcoholic beverage. Seventy volatile compounds were detected, including acids, alcohols, aldehydes, esters, ketones, and other compounds. Sensory analysis showed score of 5.93–4.57, respectively for appearance and taste. This is an important result, considering that the beverage had no flavoring additive and lacked a sweet taste. Therefore, probiotic beverages were successfully obtained by maize fermentation inoculated with co-culture of S. cerevisiae (CCMA 0731 or CCMA 0732) and L. paracasei LBC-81.
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•A new fermented functional corn-based beverage was proposed.•S. cerevisiae CCMA 0731 and CCMA 0732 maintained viability.•Several volatile compounds were found providing positive characteristics.•Sensory analysis showed score of 5.93–4.57, respectively for appearance and taste.
This study aimed to evaluate the behavior of yeasts as starter cultures for dry processed coffee. Saccharomyces cerevisiae CCMA 0543, Candida parapsilosis CCMA 0544, and Torulospora delbrueckii CCMA ...0684 were separately inoculated into coffee by directly spraying the cherries on a terrace or in buckets for 16 h before sun drying. Samples were collected and analyzed by qPCR (inoculum persistence), HPLC and GC-MS. Sensory analysis was performed on the roasted coffee. All treatments directly inoculated with yeasts showed high citric and malic acid concentrations. Caffeine, chlorogenic acids and trigonelline concentrations varied between the methods of inoculation. A total of 217 volatile compounds were identified. After roasting, volatile compounds corresponding to caramel flavor were detected in samples inoculated with Saccharomyces cerevisiae CCMA 0543 D. Fruity flavor (apple, cherry) compounds were observed in samples inoculated with Candida parapsilosis CCMA 0544 D. Saccharomyces cerevisiae CCMA 0543 inoculated in buckets obtained the highest score in the coffee cupping. Direct inoculation of Candida parapsilosis CCMA 0544 showed the best results when compared to the bucket method, while Torulospora delbrueckii CCMA 0684 showed good results for both inoculation methods evaluated.
•A new method of inoculation in coffee is proposed.•The inoculation methods presented differences in chemical and sensorial analysis.•The yeasts present different behavior according to the type of processing used.•The S. cerevisiae CCMA 0543 B obtained the best result in the sensorial score.
Summary
The probiotic strains Lactobacillus brevis CCMA1284 and Lactobacillus plantarum CCMA0359 were microencapsulated by spray drying using different matrices – whey powder (W), whey powder with ...inulin (WI) and whey powder with maltodextrin (WM). Viability of the microencapsulated strains in acid and bile juices and during 90 days of storage (seven and 25 °C) was evaluated. The two strains exhibited high encapsulation efficiency (> 86%) by spray drying. The different matrices maintained L. plantarum viability above six log CFU g−1 at 7 °C for 90 days, whereas similar results for L. brevis were observed only for W. The use of inulin as matrix of encapsulation did not enhance bacterial viability in the evaluated conditions. In general, the use of W and WM as matrices was effective for L. plantarum viability. However, only W was effective for L. brevis in the evaluated conditions. The spray drying technique was successfully adopted for the encapsulation of L. plantarum CCMA0359 and L. brevis CCMA1284 strains.
Lactobacillus brevis CCMA1284 and Lactobacillus plantarum CCMA0359 were microencapsulated by spray drying using different matrices — whey powder (W), whey powder with inulin (WI) and whey powder with maltodextrin (WM). In general, the use of W and WM as matrices was effective for L. plantarum viability and only W was effective for L. brevis.
Abstract
Yeasts are important microorganisms used in different fermentation processes. The cocoa beans must go through a correct fermentation process to obtain good-quality chocolate, which involves ...the action of yeasts and bacteria, and yeasts play a crucial role since they act in the first days of fermentation. In coffee, several studies have shown that the microbiota in the fruits is also a relevant factor. The fermentation process (regardless of the processing type) improves the beverage’s quality. In this sense, studies using starter cultures in these two raw materials are important for better control of the process, and optimization of fermentation time, in addition to the improvement and diversification of volatile and non-volatile compounds produced by yeasts. Thus, this review discusses the importance and role of yeasts during fermentation, their metabolism, the produced compounds, and how yeast and the different chemical reactions help increase the quality of chocolate and coffee.
Yeasts have a crucial role during coffee and cocoa fermentation in enhancing the quality.
Coffee quality has recently become a high demand of coffee consumers, due to all the specialty coffees available on the market. Specialty coffees can be generated by favoring growth of some groups of ...microorganisms during fermentation or by using starters. Just as yeast, a variety of bacteria can be used to generate important flavor precursors. The aim of this work was to test the efficiency of coffee sterilization and adhesion of microbial cells on beans, to evaluate the effect of yeast and bacterial starters on the production of organic and volatile compounds, and selection of potential flavor marker precursors during the wet fermentation. Three yeast and six bacterial starters were inoculated in coffee beans. Coffee sterilization and microbial adhesion was observed by scanning electron microscopy (SEM). Organic compounds were detected by high performance liquid chromatography (HPLC) and volatile compounds by gas chromatography-mass spectrometry (GC-MS). Micrographs from the SEM showed that sterilization was efficient, because there were no microbial cells after autoclaving for 5 min. Also, it was observed an increase of microbial cells from 0 to 48 h of fermentation. Malic, lactic, and acetic acid were only detected in the bacterial treatments. Volatile compounds: 4-ethenyl-1,2-dimethoxybenzene, heptadecanol, 4-hydroxy-2-methylacetophenone, and 1-butanol,2-methyl were only found in yeast treatments. Guaiacol was only produced by the inoculated
starters. In conclusion, yeast starters were better producers of volatile alcohols and bacterial starters of acid compounds. This study allowed the selection of potential flavor marker precursors, such as heptadecanol, 4-hydroxy-2-methylacetophenone, 7-methyl-4-octanol, and guaiacol.
High‐yield resistant hybrids are used in cocoa fermentation and result in chocolates with different sensorial profiles. This work aimed to characterize the fermentation microbiologically and ...physicochemically. Hybrids CEPEC 2004, FA13, PH15, and CEPEC 2002 were used for fermentation. The yeast, acetic acid bacteria, lactic acid bacteria, and mesophilic bacteria population were evaluated in their respective medium. Carbohydrates and acids were detected using a high‐performance liquid chromatography system, and volatiles were analyzed using gas chromatography‐mass spectrometry equipment. Finally, a consumer acceptance test followed by a check‐all‐that‐apply question and a temporal dominance of sensations assessment was performed in chocolate. The fermentation resulted in a typical succession: yeast‐dominated at first, followed by lactic acid, acetic acid, and mesophilic bacteria. In the pulp, carbohydrates and citric acid were consumed. Low concentrations of acetic acid (0.09–1.75 g/kg) were detected. Acids, esters, and alcohols were the most abundant groups. The chocolate profile resulted in sweet, acidic, and fruity, satisfying consumers' tastes.
Practical Application
The cocoa hybrid‐mix fermentation can improve the fermentation process and chocolate quality.
The mixture generated a different sensory profile in comparison to other fermentations.
The fruity chocolate was accepted and liked by consumers.
While many bacteria have been used as probiotics by industries, only two yeasts,
Saccharomyces cerevisiae
var.
boulardii
and
Kluyveromyces fragilis
(B0399), have been used for this purpose. In the ...present work, a total of 116 yeasts isolated from Brazilian indigenous fermented food, cocoa fermentation, and kefir were in vitro characterized for probiotic attributes. From 116 isolates, 36 were tolerant to gastrointestinal conditions evaluated by tolerance to pH 2.0, bile salts (0.3%
w
/
v
), and 37 °C temperature. From those, 15 isolates showed a similar or higher percentage (
P <
0.05) of hydrophobicity, autoaggregation, and coaggregation with
E. coli
than the reference strain
S. boulardii
. All these strains showed a high percentage of adhesion to Caco-2 cells (> 63%) and antioxidant activity (ranging from 18 to 62%). Phytate hydrolysis was evaluated for these yeasts and 13 strains showed positive results, which is important for nutrient availability in plant-based foods. These results are important insights for characterization of novel probiotic yeast strains as well as to aggregate functional value to these food products.
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