Enhancement of the aroma in low-alcohol apple-blended pear wine mixed fermented with Saccharomyces cerevisiae and non-Saccharomyces yeasts

The Antioxidant Capacity and Flavor Diversity of Strawberry Wine Are Improved Through Fermentation with the Indigenous Non-Saccharomyces Yeasts Hanseniaspora uvarum and Kurtzmaniella quercitrusa

The production of strawberry wine is an effective strategy for addressing the significant economic losses caused by strawberry spoilage. In recent years, there has been an increase in consumer demand for quality and flavor diversity in fruit wines. Therefore, it is necessary to develop novel strawberry wine products. In this research, we assessed and analyzed the influences of fermentation with Hanseniaspora uvarum, Kurtzmaniella quercitrusa, and Saccharomyces cerevisiae under four fermentation conditions on the fermentation kinetics, organoleptic characteristics, chemical compositions, antioxidant capacities, and flavor profiles of strawberry wines. Strawberry wines fermented with the indigenous non-Saccharomyces yeasts H. uvarum and K. quercitrusa showed higher 2,2-Diphenyl-1-picrylhydrazyl (DPPH) and 2,2'-Azinobis-(3-ethylbenzothiazoline-6-sulfonate) (ABTS) free-radical-scavenging capacities and significantly different flavor profiles compared to strawberry wines fermented with S. cerevisiae. In addition, adjusting the initial soluble solids contents of strawberry juices and fermentation temperatures positively affected the quality and flavor profiles of strawberry wines fermented with the H. uvarum and K. quercitrusa strains. Under the condition of 18 °C-20 °Brix, strawberry wine fermented with K. quercitrusa presented the highest antioxidant capacity, with enhanced flavor diversity and color intensity. It is worth noting that K. quercitrusa can be an alternative yeast for producing high-quality strawberry wine with a distinct floral aroma.

Effects of glycosidases and GSH pretreatments, fermentation temperatures, and aging time on the physicochemical, organic acids, and aroma profiles of perry

The lack of sufficient flavour in perry represents a barrier to its further industrialization. This study aimed to investigate the effects of glutathione (GSH), β-glucosidase (Glu), and α-L-rhamnosidase (Rha) pretreatments, the fermentation temperature from 16 °C to 28 °C, and the aging time of 1, 2, and 3 years (PA1, PA2, and PA3) on the physicochemical properties, organic acids, and aroma profiles were investigated. The results demonstrated that the synergistic effect of Glu, Rha, and GSH was more effective than their individual or paired applications in enhancing the varietal aromas. The contents of terpenes, phenols, acetate and ethyl esters in the Glu + Rha + GSH treatment were significantly increased in comparison to the control, with improvements of 60.77 %, 118.64 %, 77.02 %, and 32.82 %, respectively. The OAV flavor profile showed rich floral, fruity, and citrus aromas. The contents of tartaric acid and quinic acid decreased from 16 °C to 28 °C, whereas lactic acid was the opposite. Except for phenethyl acetate and ethyl decanoate, the contents of acetate and ethyl esters exhibited a decline at elevated temperatures, whereas isopentanol and phenylethyl alcohol increased. The contents of esters and phenols at 16 °C increased significantly, whereas those of alcohols decreased. This contributed to banana, floral, fruity, orange peel, and spices aromas to the fermentation aromas. The difference in organic acid profiles between PA3 and PA1, PA2 were obvious, the contents of acetic acid and citric acid in PA3 decreased significantly, whereas those of tartaric acid, L-malic acid, and lactic acid increased. The contents and proportions of acetate and medium-chain fatty acid ethyl esters decreased from PA1 to PA3, while the ethyl esters resulted from esterification reactions increased, and the contents of alcohols and acids constituents were different between the three years. The contents of esters, phenols, and total volatiles increased significantly, while the aging aroma was markedly enhanced in PA3. It can be concluded that the Glu + Rha + GSH pretreatment, fermentation at 16 °C, and aging for three years exhibited the great aroma potential of perry, which enhanced the flavor intensity through the regulation of varietal, fermentation, and aging aromas.

Effects of mixed fermentation on the flavor quality and in vitro antioxidant activity of Zaosu pear-Merlot grape composite alcoholic beverage

In this study, a mixed fermentation strategy using grape-blended pear juice co-inoculated with Metschnikowia pulcherrima 346 and Saccharomyces cerevisiae ES488 was used to characterize the modifications of the flavor and antioxidant activity of Zaosu pear-Merlot grape alcoholic beverage. The optimum fermentation parameters identified using a fuzzy mathematical sensory evaluation model were an initial pH of 4.22, a ratio of M. pulcherrima 346 and S. cerevisiae ES488 inoculated 1.13:1, sequential inoculation time 47.02 h and making temperature 19 °C. The optimal mixed fermentation increased the content of terpenes and ethyl esters in pear-grape beverage by 16.5 % and 11.2 % respectively, enhancing floral and fruity aromas and attaining the highest sensory score. Due to the accumulation of flavonoid, anthocyanin, and phenol, the optimized alcoholic beverage exhibited the highest DPPH (97.6 %) and OH (93.3 %) radical scavenging rate as well as iron ion reducing power (3.25), which is conducive to extending the shelf life of beverages.

Dissecting Interactions of Saccharomyces cerevisiae and Pichia kudriavzevii to Shape Kiwifruit Wine Flavor

Mixed fermentation with Saccharomyces cerevisiae and Pichia kudriavzevii has been shown to enhance wine aroma, yet the underlying mechanisms remain unclear. Monoculture of S. cerevisiae, monoculture of P. kudriavzevii, and mixed culture of S. cerevisiae and P. kudriavzevii were conducted, and the study analyzed and compared the biomass, flavor profile, and transcriptome responses of the three groups. Both yeast species exhibited growth inhibition in mixed culture, especially P. kudriavzevii. Significant differences were observed in three organic acids and the foremost 20 volatile compounds. Mixed fermentation enhanced esters (e.g., ethyl butyrate, isoamyl acetate) and volatile acids (e.g., hexanoic acid), but decreased isobutanol, phenylethyl alcohol, and quinic acid. Transcriptomic analysis revealed 294 and 332 differentially expressed genes (DEGs) in S. cerevisiae and P. kudriavzevii, respectively. The Kyoto Encyclopedia of Genes and Genomes (KEGG) annotation results indicated that DEGs in mixed fermentation were concentrated in carbohydrate metabolism and amino acid metabolism. Our integrated analysis suggested that genes such as TDH2, TDH3, and ENO2 were pivotal for ester biosynthesis. Moreover, ADH1, ADH2, HPA3, ALD6, and ARO8 were associated with quinic acid synthesis. Furthermore, ILV2, ILV5, ALD6, and others were central to the production of isobutanol and phenylethyl alcohol.

Lactiplantibacillus plantarum exerts strain-specific effects on malolactic fermentation, antioxidant activity, and aroma profile of apple cider

This study aimed to investigate the impact of different strains of Lactiplantibacillus plantarum on malolactic fermentation (MLF), antioxidant activity, and aroma of ciders. A commercial strain of Saccharomyces cerevisiae and six indigenous L. plantarum strains were co-inoculated into apple juice to induce simultaneous alcoholic fermentation (AF) and MLF. The findings indicated that despite belonging to the same species, the different L. plantarum strains significantly differed (p < 0.05) in terms of antioxidant activity and aroma compounds in the ciders. MLF induced by L. plantarum resulted in the substantial consumption of malic acid and increased levels of lactic acid in the ciders, with strain-specific effects observed, particularly with L. plantarum SCFF284. In addition, ciders produced from mixed fermentations exhibited higher levels of antioxidant activity than those from pure S. cerevisiae fermentation (p < 0.05), especially for LAM284. Furthermore, ciders produced from mixed fermentations exhibited higher levels of aroma compounds, such as ethyl acetate and isoamyl alcohol, and also received higher sensory scores compared to ciders produced through pure S. cerevisiae fermentation (p < 0.05). These results highlight the effectiveness of MLF induced by L. plantarum in enhancing the antioxidant activity and aroma profile of ciders.

Effects of Cultivar Factors on Fermentation Characteristics and Volatile Organic Components of Strawberry Wine

Strawberry wine production is a considerable approach to solve the problem of the Chinese concentrated harvesting period and the short shelf life of strawberries, but the appropriative strawberry cultivars for fermentation are still undecided. In this study, the strawberry juice and wines of four typical strawberry cultivars named Akihime (ZJ), Sweet Charlie (TCL), Snow White (BX), and Tongzhougongzhu (TZ) were thoroughly characterized for their physicochemical indicators, bioactive compounds, and volatile organic components (VOCs) to determine the optimal strawberry cultivars for winemaking. The results showed that there were significant differences in the total sugar content, pH, total acid, and other physicochemical indexes in the strawberry juice of different cultivars, which further affected the physicochemical indexes of fermented strawberry wine. Moreover, the content of polyphenols, total flavonoids, vitamin C, and color varied among the four strawberry cultivars. A total of 42 VOCs were detected in the strawberry juice and wines using headspace solid-phase microextraction coupled with gas chromatography-mass spectrometry (HS-SPME-GC-MS), and 3-methyl-1-butanol, linalool, trans-2-pinanol, hexanoic acid, and hexanoic acid ethyl ester were the differential VOCs to identify the strawberry wine samples of different cultivars. Overall, strawberry cultivar ZJ had a relatively high VOC and bioactive compound content, indicating that it is the most suitable cultivar for strawberry wine fermentation. In addition to determining the relatively superior fermentation characteristics of cultivar ZJ, the results may provide a theoretical basis for the raw material quality control and quality improvement of strawberry wine.

Enhancing the flavour quality of Laiyang pear wine by screening sorbitol-utilizing yeasts and co-fermentation strategies

This study took a novel approach to address the dual challenges of enhancing the ethanol content and aroma complexity in Laiyang pear wine. It focused on sorbitol as a pivotal element in the strategic selection of yeasts with specific sorbitol-utilization capabilities and their application in co-fermentation strategies. We selected two Saccharomyces cerevisiae strains (coded as Sc1, Sc2), two Metschnikowia pulcherrima (coded as Mp1, Mp2), and one Pichia terricola (coded as Tp) due to their efficacy as starter cultures. Notably, the Sc2 strain, alone or with Mp2, significantly increased the ethanol content (30% and 16%). Mixed Saccharomyces cerevisiae and Pichia terricola fermentation improved the ester profiles and beta-damascenone levels (maximum of 150%), while Metschnikowia pulcherrima addition enriched the phenethyl alcohol content (maximum of 330%), diversifying the aroma. This study investigated the efficacy of strategic yeast selection based on sorbitol utilization and co-fermentation methods in enhancing Laiyang pear wine quality and aroma.

Effect of different inoculation strategies of mixed culture Saccharomyces cerevisiae/Oenococcus oeni on the aroma quality of Chardonnay wine

There has been growing interest in the use of mixed cultures comprised of Oenococcus oeni and Saccharomyces cerevisiae to produce wine with local style and typicality. This study has investigated the influence of the inoculation protocol of O. oeni on the fermentation kinetics and aromatic profile of Chardonnay wine. The one selected autochthonous O. oeni strain (ZX-1) inoculated at different stages of the alcoholic fermentation process successfully completed malolactic fermentation (MLF). Co-inoculum of S. cerevisiae and O. oeni enabled simultaneous alcoholic fermentation and MLF, leading to at least a 30 % reduction in the total fermentation time when compared to the sequential inoculation process, which was attributed to the lower ethanol stress. Meanwhile, co-inoculum stimulated the accumulation of volatile aroma compounds in Chardonnay wine. In particular, the mixed modality where the O. oeni strain ZX-1 was inoculated 48 h after S. cerevisiae allowed higher levels of terpenes, acetates, short-chain, and medium-chain fatty acid ethyl esters to be produced, which may result in the enhanced floral and fruity attributes of wine. Aroma reconstitution and omission models analysis revealed that the accumulation of linalool, geraniol, isoamyl acetate, ethyl hexanoate, and ethyl caprylate during the mixed fermentation process enhanced the stone fruit, tropical fruit, and citrus aromas in Chardonnay wine. Therefore, the simultaneous fermentation of S. cerevisiae and autochthonous O. oeni ZX-1 has a positive effect on MLF and contributes to producing wines with distinctive style.

Succession of microbiota and its influence on the dynamics of volatile compounds in the semi-artificial inoculation fermentation of mulberry wine

To improve the delightful flavor of mulberry wine through semi-artificial inoculation fermentation with Saccharomyces cerevisiae, we studied the dynamics change of microbiota, along with the physicochemical properties and metabolite profiles and their interaction relationship during the fermentation process. The abundance of lactic acid bacteria (Weissella, Lactobacillus, Fructobacillus, and Pediococcus) increased significantly during fermentation, while yeasts gradually established dominance. The inter-kingdom network of the dominant genera analysis further identified the following as core microbiota: Alternaria, Botrytis, Kazachstania, Acremonium, Mycosphaerella, Pediococcus, Gardnerella, and Schizothecium. Additionally, pH, alcohol, and total acid were significantly affected by microbiota variation. Fourteen of all identified volatile compounds with key different aromas were screened using PCA, OPLS-DA, and rOAV. The network of interconnected core microbiota with key different aromas revealed that Kazachstania and Pediococcus had stronger correlations with 1-butanol, 3-methyl-, propanoic acid, and 2-methyl-ethyl ester.

Comparison of phenolic composition and sensory quality among pear beverages made using Saccharomyces cerevisiae and Torulaspora delbrueckii

The effects of Saccharomyces cerevisiae and Torulaspora delbrueckii on phenolic composition and sensory quality were characterized in the production of alcoholic beverages from selected pear cultivars with diverse biochemical characteristics. The fermentation process generally affected the phenolic composition by increasing the contents of hydroxycinnamic acids and flavan-3-ols and reducing the levels of hydroxybenzoic acids, procyanidins, and flavonols. Although the phenolic compositions and sensory properties of pear beverages depended primarily on pear cultivar selection, the applied yeast strains also played important roles in beverage quality. Fermentation with T. delbrueckii resulted in higher caffeoylquinic acid and quercetin-3-O-glucoside contents, higher rated intensities of 'cooked pear' and 'floral' odors and a sweeter taste than fermentation with S. cerevisiae. Moreover, higher concentrations of hydroxybenzoic acids, hydroxycinnamic acids, and flavonols correlated closely with astringency perception. Applying T. delbrueckii strains and breeding novel pear cultivars are important approaches to produce fermented beverages of high quality.

Optimization of the Brewing Process and Analysis of Antioxidant Activity and Flavor of Elderberry Wine

Fruit wines have high nutritional value and good palatability. However, fruit wine made from a single fruit type does not have good enough flavor and nutritional quality. Therefore, flavorsome fruit wines made from a variety of fruits should be developed as a matter of urgency. In this study, the raw material of elderberry wine was used to explore the production technology of mixed juice wines; the fruits selected were apple, lychee, pear, blueberry, and elderberry. We utilized a single-factor experiment and the response surface method (RSM) approach to optimize the fermentation procedures; the results show that the solid–liquid ratio was 1:7.5, the amount of yeast inoculation was 0.68 g/L, the fermentation temperature was 20 °C, and the added sugar content was 120 g/L. Under these process conditions, a verification test was carried out in a 35 L fermenter. The results showed that the alcohol content, residual sugar content, total acidity, total phenol content, and total flavonoid content of the elderberry wine were, respectively, 7.73% vol, 8.32 g/L, 9.78 g/L, 8.73 mg/mL, and 1.6 mg/mL. In total, 33 volatile components were identified in the resulting elderberry wine. It achieved a harmonious aroma and fruit flavor, a homogeneous and transparent liquid phase, a pleasant taste, and a sensory evaluation score of 95. The antioxidant activity experiments showed that elderberry had a certain antioxidant capacity, and that fermented elderberries had significantly higher antioxidant ability than unfermented ones.

Quality Improvement in Apple Ciders during Simultaneous Co-Fermentation through Triple Mixed-Cultures of Saccharomyces cerevisiae, Pichia kudriavzevii, and Lactiplantibacillus plantarum

This study explored the effect of the combination of Saccharomyces yeast, non-Saccharomyces yeast (Pichia kudriavzevii), and Lactiplantibacillus plantarum during cider fermentation on physicochemical properties, antioxidant activities, flavor and aroma compounds, as well as sensory qualities. Ciders fermented with the triple mixed-cultures of these three species showed lower acid and alcohol content than those fermented with the single-culture of S. cerevisiae. The antioxidant activities were enhanced by the triple mixed-culture fermentation, giving a higher 1,1-diphenyl-2-picrylhydrazyl (DPPH) radical scavenging rate and total antioxidant capacity; specifically, the SPL5 cider showed the highest DPPH radical scavenging rate (77.28%), while the SPL2 gave the highest total antioxidant capacity (39.57 mmol/L). Additionally, the triple mixed-culture fermentation resulted in improved flavor and aroma with a lower acidity (L-malic acid) and higher aroma compounds (Esters), when compared with the single-culture fermented ciders (Saccharomyces cerevisiae); more specifically, the SPL4 cider resulted in the highest total flavor and aroma compounds. In addition, sensory evaluation demonstrated that ciders produced using the triple mixed-cultures gained higher scores than those fermented using the single-culture of S. cerevisiae, giving better floral aroma, fruity flavor, and overall acceptability. Therefore, our results indicated that the triple mixed-cultures (S. cerevisiae, P. kudriavzevii, and L. plantarum) were found to make up some enological shortages of the single S. cerevisiae fermented cider. This study is believed to provide a potential strategy to enhance cider quality and further give a reference for new industrial development protocols for cider fermentation that have better sensory qualities with higher antioxidant properties.

Application of yeast in plant-derived aroma formation from cigar filler leaves

Introduction: There are various degrees of defects of cigar filler leaves after air drying. Methods: In order to improve the quality and plant-derived aroma content of cigar filler leaves, nine aroma-producing yeasts were applied in artificially solid-state fermentation of cigar filler leaves in this study. The differences with various yeasts application were compared by chemical composition and GC-MS analysis. Results and discussion: The results showed that 120 volatile components were identified and quantified in cigar filler leaves after fermentation, including aldehydes (25 types), alcohols (24 types), ketones (20 types), esters (11 types), hydrocarbons (12 types), acids (4 types) and other substances (23 types). Based on the analysis of odor activity value (OAV), the OVA of fruity and floral aroma components were higher. It was found that floral aroma are the representative aroma types of cigar filler leaves treated with Clavispora lusitaniae, Cyberlindera fabianii, Saccharomycosis fibuligera and Zygosaccharomyces bailii R6. After being inoculated with Hanseniaspora uvarum J1, Hanseniaspora uvarum J4 and Pichia pastoris P3, the OAV of fruity aroma in cigar filler leaves was the highest, followed by tobacco aroma and woody aroma. The correlation between volatile components of cigar filler leaves with different yeasts was revealed after PCA analysis. It was concluded that the quality of cigar filler leaves was improved, and cigar filler leaves fermented with different yeasts showed different flavor.

Optimization of the Quality of Chestnut Rose Jiaosu Compound Beverage Based on Probiotic Strains and Fermentation Technology

Chestnut rose is an endemic plant in Guizhou Province, China, also known as seedless prickly pear, rich in mineral elements, vitamin C, and flavonoids. With chestnut rose as the main raw material, with grapes, apples, and other fruits as auxiliary ingredients, through the technical process of deastringency, sterilization, fermentation, blending, and other technical processes to obtain the composite beverage, known as a chestnut rose jiaosu compound beverage, it is hereinafter referred to as CRJCB. The CRJCB fermented from chestnut rose juice is nutritious and has a variety of health effects, and the flavor is unique, with good color, aroma, and taste, which is a new type of beverage. However, at present, the fermentation related technology of CRJCB is not perfect, resulting in its low quality, which seriously restricts the industrialization development of CRJCB. In order to improve the quality of the jiaosu compound beverage, probiotics such as Lactobacillus delbrueckii subsp. Bulgaricus, Lactobacillus casei, Lactobacillus royale (Lactobacillus reuteri), Lactobacillus acidophilus, and Streptococcus thermophilus, etc., were used. The chestnut rose as the main raw material was used for the fermentation, and grapes, apples, and sugar were used as auxiliary materials to carry out the research on the fermentation of single or mixed probiotics. The key fermentation processes affecting the quality of the jiaosu, such as juice preparation, deastringency of chestnut rose juice, fermentation temperature and time, sugar addition, and taste mixing of the jiaosu, were optimized. The optimized ratio, fermentation process parameters, and strains of probiotics of compound beverage with chestnut rose jiaosu, with high quality, were obtained. The experimental results showed that the SOD enzyme activity value was 167.7 U·ml−1, the vitamin C content was 1154.5 mg/100 mL, the soluble solids content was 5.80%, and the nitrite content was 89.8 mg/kg in the compound beverage with chestnut rose jiaosu, obtained by using the optimized ratio and fermentation process parameters proposed in this paper. The development and utilization of chestnut rose resources provide a new idea and is of great significance in promoting the development of the chestnut rose industry.

Effect of Deacidification Treatment on the Flavor Quality of Zaosu Pear–Kiwifruit Wine

Conventional pear–kiwifruit wine has a bland flavor and sour taste, because of excessive l-malic acid content and, consequently, little consumer appeal. An Oenococcus oeni strain, GF-2, has good malolactic fermentation (MLF) performance and high glucosidase activity. Through a Box–Behnken design, the optimum MLF parameters for deacidification by GF-2 were determined: initial pH of 3.4, 5% v/v inoculation, and temperature of 20 °C, which reduced the malic acid content by 98.3%. The changes in the content of organic acids, polyphenols, and aromatic compounds after MLF were compared with chemical deacidification. MLF significantly decreased the total concentration of organic acids by 29.7% and promoted the accumulation of aromatic esters, higher alcohols, and terpenoids, but chemical deacidification markedly decreased aromatic compound content by 59.8%. MLF wine achieved the highest sensory scores for aroma, taste, and overall acceptability. Therefore, MLF with O. oeni GF-2 has great potential to markedly improve the quality of commercial pear–kiwifruit wine.