Evaluation of the quality of fermented kiwi wines made from different kiwifruit cultivars

Effects of an inoculation dose of Issatchenkia terricola WJL-G4 on physicochemical properties, active substances, and antioxidant capacity of black, red, and white currant juice

BACKGROUND

Due to the high level of organic acids - primarily citric acid - black, red, and white currants have an excessively sour taste, making taste adjustment during processing challenging. This study investigated and evaluated the effects of an inoculation dose of the acid-reducing yeast Issatchenkia terricola WJL-G4 on several aspect such as physicochemical properties, chromaticity, active substances, and antioxidant capacity. A sensory evaluation was also conducted.

RESULTS

The results indicated that, when the inoculation dose increased from 2% to 12%, the total phenol, total flavonoid, and total anthocyanin content, and antioxidant capacity in currant juice decreased. A low inoculation dose (2-4%) was beneficial for preserving the total phenol and total flavonoid content. Although the levels of most phenolic compounds decreased, the concentrations of caffeic acid, p-coumaric acid, ferulic acid, rutin, and epicatechin were significantly higher than the control after fermentation. Overall acceptability and taste scores of fermented currants improved compared with those of the control group.

CONCLUSION

This experiment provided an effective solution, with a theoretical basis, to the problems of the sour taste and harsh flavor of currant juice. © 2024 Society of Chemical Industry.

Impact of must clarification treatments on chemical and sensory profiles of kiwifruit wine

This study examined the effect of various clarification treatments on the physicochemical properties, volatile compounds, and sensory attributes of kiwi wines produced from five different kiwifruit (Actinidia deliciosa) varieties. The degree of clarification had a minimal impact on physicochemical parameters, including the content of residual sugar, ethanol, volatile acid, titratable acidity (except for the kiwifruit variety 'Qinmei'), and the pH value. However, wines made from unclarified juices (muddy juice and pulp) displayed a higher glycerol content than those made from clarified juices. The cluster heat map and principal component analyses (PCA) demonstrated that kiwi wines produced from clarified kiwi juices possessed a higher ester content, whereas muddy juice and pulp wines contained elevated levels of higher alcohols. Quantitative descriptive analysis (QDA) indicated that clarified juice wines outperformed muddy juice and pulp wines in terms of purity, typicality, harmony, intensity, and freshness, with negligible differences in terms of palate acidity. Moreover, the clarified juice wines featured more characteristic kiwi wine aromas (kiwifruit, passionfruit, and pineapple) compared with that of the muddy juice and pulp wines, which exhibited an increased grassy flavour. Although the 100-NTU kiwifruit juice-fermented wine did not show an advantage in the cluster heat map and PCA, it presented better freshness, typicality, and intensity in the QDA, as well as a more passionfruit aroma. Based on the orthogonal partial least-squares discriminant analysis, A. deliciosa 'Xuxiang' was deemed to be the most suitable variety for vinification. This study provides crucial insights for enhancing the production of high-quality kiwi wine.

Orange passion fruit (Passiflora caerulea L.) as a new raw material for acetic fermentation: evaluation of organic acids and phenolic profile, in vitro digestion, and biological activities

BACKGROUND

This study evaluated for the first time the potential of orange passion fruit as a base for alcoholic and acetic fermentations, with a view to assessing its profile of organic acids and polyphenols, in vitro digestion, and biological activities.

RESULTS

In terms of aliphatic organic acids, malic acid was the majority in the wine (3.19 g L-1), while in the vinegar, it was acetic acid (46.84 g L-1). 3,4-Dihydroxybenzoic acid (3,4-DHB) was the major phenolic compound in the wine and vinegar samples (3443.93 and 2980.00 μg L-1, respectively). After the in vitro gastrointestinal simulation stage, the wine showed high bioaccessibility for the compounds sinipaldehyde (82.97%) and 2,4-dihydroxybenzoic acid (2,4-DHBA, 81.27%), while the vinegar exhibited high bioaccessibility for sinipaldehyde (89.39%). Through multivariate analysis, it was observed that 3,4-DHB was highly concentrated in the different digested fractions obtained from the wine. In contrast, in the vinegar, the stability of isorahmenetin and Quercetin 3-o-rhamnoside was observed during the in vitro digestion simulation. Lastly, the vinegar stood out for its inhibition rates of α-amylase (23.93%), α-glucoside (18.34%), and angiotensin-converting enzyme (10.92%). In addition, the vinegar had an inhibitory effect on the pathogenic microorganisms Salmonella enteritidis, Escherichia coli, and Listeria monocytogenes.

CONCLUSION

Orange passion fruit has proved to be a promising raw material for the development of fermented beverages. Therefore, this study provides an unprecedented perspective on the use and valorization of orange passion fruit, contributing significantly to the advancement of knowledge about fermented products and the associated nutritional and functional possibilities. © 2024 Society of Chemical Industry.

Comparison of Aroma and Taste Profiles of Kiwi Wine Fermented with/without Peel by Combining Intelligent Sensory, Gas Chromatography-Mass Spectrometry, and Proton Nuclear Magnetic Resonance

Kiwi wine (KW) is tipically made by fermenting juice from peeled kiwifruit, resulting in the disposal of peel and pomace as by-products. However, the peel contains various beneficial compounds, like phenols and flavonoids. Since the peel is edible and rich in these compounds, incorporating it into the fermentation process of KW presents a potential solution to minimize by-product waste. This study compared the aroma and taste profiles of KW from peeled (PKW) and unpeeled (UKW) kiwifruits by combining intelligent sensory technology, GC-MS, and 1H-NMR. Focusing on aroma profiles, 75 volatile organic compounds (VOCs) were identified in KW fermented with peel, and 73 VOCs in KW without peel, with 62 VOCs common to both. Among these compounds, rose oxide, D-citronellol, and bornylene were more abundant in UKW, while hexyl acetate, isoamyl acetate, and 2,4,5-trichlorobenzene were significantly higher in PKW. For taste profiles, E-tongue analysis revealed differences in the taste profiles of KW from the two sources. A total of 74 molecules were characterized using 1H-NMR. UKW exhibited significantly higher levels of tartrate, galactarate, N-acetylserotonin, 4-hydroxy-3-methoxymandelate, fumarate, and N-acetylglycine, along with a significantly lower level of oxypurinol compared to PKW. This study seeks to develop the theoretical understanding of the fermentation of kiwifruit with peel in sight of the utilization of the whole fruit for KW production, to increase the economic value of kiwifruit production.

Physicochemical and Volatile Compounds Analysis of Fruit Wines Fermented with Saccharomyces cerevisiae: FTIR and Microscopy Study with Focus on Anti-Inflammatory Potential

The growing trend in fruit wine production reflects consumers' interest in novel, diverse drinking experiences and the increasing demand for healthier beverage options. Fruit wines made from kiwi, pomegranates, and persimmons fermented using S. bayanus Lalvin strain EC1118 demonstrate the versatility of winemaking techniques. Kiwifruit, persimmon, and pomegranate wines were analyzed using HPLC and GC-TOFMS analyses to determine their concentrations of phenolic acids and volatile compounds. These results were supported by Fourier transform infrared (FTIR) spectroscopy to characterize and compare chemical shifts in the polyphenol regions of these wines. The wines' characterization included an anti-inflammatory assay based on NO, TNF-alpha, and IL-6 production in the RAW 264.7 macrophage model. FTIR spectroscopy predicted the antioxidant and phenolic contents in the wines. In terms of polyphenols, predominantly represented by chlorogenic, caffeic, and gallic acids, pomegranate and kiwifruit wines showed greater benefits. However, kiwifruit wines exhibited a highly diverse profile of volatile compounds. Further analysis is necessary, particularly regarding the use of other microorganisms in the fermentation process and non-Saccharomyces strains methods. These wines exhibit high biological antioxidant potential and health properties, providing valuable insights for future endeavors focused on designing healthy functional food products.

Effects of Torulaspora delbrueckii and Saccharomyces cerevisiae Co-Fermentation on the Physicochemical and Flavor Compounds of Huaniu Apple Cider

The effects of different fermentation methods utilizing Torulaspora delbrueckii 1004 and Saccharomyces cerevisiae 32169 on the physicochemical properties, organic acid content, polyphenol and flavonoid concentrations, antioxidant activity, and volatile aroma compounds of Huaniu apple cider were investigated in this study. Employing methods of single inoculation, co-inoculation, and sequential inoculation, it was found that sequential fermentation exhibited strong fermentative power in the initial stages, effectively reducing the content of soluble solids and achieving a balanced composition of malic, succinic, and citric acids while maintaining a lower titratable acidity. Sequential inoculation was observed to significantly enhance the total polyphenols and flavonoids, as well as the antioxidant capacity (p < 0.05). Specifically, in the synthesis of volatile aroma compounds, sequential inoculation significantly enhanced the richness and diversity of the Huaniu apple cider's aromas, particularly in terms of the concentration of ester compounds (p < 0.05). Principal component analysis further confirmed the superiority of sequential inoculation in terms of aroma component diversity and richness. The findings of this study suggest that sequential inoculation of fermentation with non-Saccharomyces and S. cerevisiae is an effective strategy for optimizing the flavor characteristics of Huaniu apple cider, offering valuable theoretical support and practical guidance for enhancing cider quality and fostering the development of new products.

Application of Cyclocarya paliurus-Kiwifruit Composite Fermented to Enhance Antioxidant Capacity, Flavor, and Sensory Characteristics of Kiwi Wine

A new fermentation method for kiwi wine was explored by developing the well-known medicinal and edible plant Cyclocarya paliurus (C. paliurus) to create more value with undersized kiwifruits. In this study, the changes in bioactive substances during the C. paliurus-kiwi winemaking process were analyzed on the basis of response surface optimization results, and the antioxidant capacity, aromatic compounds, and sensory quality of the C. paliurus-kiwi composite wine with kiwi wine and two commercial kiwi wines were compared. The results showed that DPPH radical, OH- radical, and ABTS+ scavenging rates remained at over 60.0%, 90.0%, and 70.0% in C. paliurus-kiwi wine, respectively. The total flavonoid content (TFC) and total polyphenol content (TPC) of C. paliurus-kiwi wine were significantly higher than those of the other three kiwi wines. C. paliurus-kiwi wine received the highest score and detected 43 volatile compounds. Ethyl hexanoate, which showed stronger fruity and sweet aromas, was one of the main aroma components of C. paliurus-kiwi wine and different from commercial wines. This wine has a good flavor with a natural and quality feeling of C. paliurus-kiwifruit extract, low-cost processing, and great market potential.

Comprehensive Evaluation of Ten Actinidia arguta Wines Based on Color, Organic Acids, Volatile Compounds, and Quantitative Descriptive Analysis

Actinidia arguta wine is a low-alcoholic beverage brewed from A. arguta with a unique flavor and sweet taste. In this study, the basic physicochemical indicators, color, organic acid, and volatile aroma components of wines made from the A. arguta varieties 'Kuilv', 'Fenglv', 'Jialv', 'Wanlv', 'Xinlv', 'Pinglv', 'Lvbao', 'Cuiyu', 'Tianxinbao', and 'Longcheng No.2' were determined, and a sensory evaluation was performed. The findings show that 'Tianxinbao' produced the driest extract (49.59 g/L), 'Kuilv' produced the most Vitamin C (913.46 mg/L) and total phenols (816.10 mg/L), 'Jialv' produced the most total flavonoids (477.12 mg/L), and 'Cuiyu' produced the most tannins (4.63 g/L). We analyzed the color of the A. arguta wines based on CIEL*a*b* parameters and found that the 'Kuilv' and 'Longcheng No.2' wines had the largest L* value (31.65), the 'Pinglv' wines had the greatest a* value (2.88), and the 'Kuilv' wines had the largest b* value (5.08) and C*ab value (5.66) of the ten samples. A total of eight organic acids were tested in ten samples via high-performance liquid chromatography (HPLC), and we found that there were marked differences in the organic acid contents in different samples (p < 0.05). The main organic acids were citric acid, quinic acid, and malic acid. The aroma description of a wine is one of the keys to its quality. A total of 51 volatile compounds were identified and characterized in ten samples with headspace gas chromatography-ion mobility spectrometry, including 24 esters, 12 alcohols, 9 aldehydes, 3 aldehydes, 2 terpenes, and 1 acid, with the highest total volatile compound content in 'Fenglv'. There were no significant differences in the types of volatile compounds, but there were significant differences in the contents (p < 0.05). An orthogonal partial least squares discriminant analysis (OPLS-DA) based on the odor activity value (OAV) showed that ethyl butanoate, ethyl pentanoate, ethyl crotonate, ethyl isobutyrate, butyl butanoate, 2-methylbutanal, ethyl isovalerate, and ethyl hexanoate were the main odorant markers responsible for flavor differences between all the A. arguta wines. Sensory evaluation is the most subjective and effective way for consumers to judge A. arguta wine quality. A quantitative descriptive analysis (QDA) of the aroma profiles of ten grapes revealed that the 'fruity' and 'floral' descriptors are the main and most essential parts of the overall flavor of A. arguta wines. 'Tianxinbao' had the highest total aroma score. The flavor and quality of A. arguta wines greatly depend on the type and quality of the A. arguta raw material. Therefore, high-quality raw materials can improve the quality of A. arguta wines. The results of the study provide a theoretical basis for improving the quality of A. arguta wines and demonstrate the application prospects of HS-GC-IMS in detecting A. arguta wine flavors.

Cultivar difference characterization of kiwifruit wines on phenolic profiles, volatiles and antioxidant activity

Antioxidant activity and volatiles of kiwifruit wine with different flesh colors were investigated in this study. Green (Guichang and Xuxiang), red (Donghong and Hongyang), and yellow (Jinyan) kiwifruits were analyzed to determine their alcohol content, phenolic profiles, antioxidant activity, and aroma composition. The results showed that Hongyang and Donghong wines had higher antioxidant activity and content of antioxidant substances. Hongyang wine possessed the most abundance of polyphenolic compounds, chlorogenic acid and catechins were the main polyphenols of kiwi wines. The 101 aromatic components were detected, Xuxiang wine possessed 64 aromatic compounds, Donghong and Hongyang wines had the higher esters compositions, 79.87%, and 78.0% respectively. From PCA (Principal Component Analysis), the volatile substances of kiwi wine with the same flesh color were similar. Five kinds of kiwi wines shared 32 kinds of volatile compounds, these compounds may be the core volatiles in kiwi wine. Therefore, the color of kiwi flesh can impact wine flavor, with Hongyang and Donghong kiwis owning red flesh being the most suitable for producing kiwi wine which would be a new milestone to the wine manufactures.

Effects of Pectinase Pre-Treatment on the Physicochemical Properties, Bioactive Compounds, and Volatile Components of Juices from Different Cultivars of Guava

In this study, the physicochemical properties, antioxidant capacity, and volatile compounds of the juices of different guava cultivars before and after pectinase treatment were evaluated. The results showed that the guava juice of the small fragrant (SF) cultivar exhibited the highest ascorbic acid concentration (1761.09 mg/L), and the highest contents of total phenolics (329.52 mg GAE/L) and total flavonoids (411.13 mg RE/L) were both found in the juice of the watermelon red (WR) cultivar. After pectinase treatment, the juice yield and the titratable acid, sugar components, total phenolics and total flavonoids, and antioxidant capacity levels of the guava juices were all higher than those of the non-pectinase group. However, lower sensory evaluation scores were obtained in the pectinase-treated guava juices. Aldehydes and terpenoids were the main flavor components in the guava juices, which were responsible for the aroma of the juice, while their relative contents were different in the four cultivar guava juices. Furthermore, pectinase treatment could change the amounts and relative contents of volatile compounds in the guava juice. During the pectinase treatment process, the relative contents of the main aroma constituents in the guava juices were significantly decreased. The findings of this research provide valuable information for the processing of guava juice.

Effects of Blending on Phenolic, Colour, Antioxidant and Aroma Components of Cabernet Sauvignon Wine from Xinjiang (China)

High-quality wines in industrial winemaking frequently require a professional winemaker to make adjustments according to the wine of single-batch fermentation. Blending can improve the chemical composition and certain organoleptic properties of wine, promote copigmentation, and increase the complexity of the wine body and aroma. In this study, high-performance liquid chromatography (HPLC) and headspace solid-phase microextraction with gas chromatography coupled to tandem mass spectrometry (HS-SPME-GC-MS/MS) were used to study the effects of adding 20% of Merlot, Marselan, Syrah and Pinot Noir and different blending methods on the nutritional, taste, color and aroma components of Cabernet Sauvignon wine. The results showed that the highest total phenols and flavonoids, the greatest content of antioxidant characteristics, the optimal color according to the parameter of T, red% and blue% and the most abundant aroma were observed both in CGM (grape blending Cabernet Sauvignon and Merlot) and CGS (grape blending Cabernet Sauvignon and Marselan), thus indicating the higher quality and complexity of these wines. In addition, the co-grapes treatment afforded more color and hue value than co-wines, which indicates co-grapes had more stable and more varied colors than co-wines. Our findings provide theoretical support for improving wine quality and craftsmanship.

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.