Optimization of fermentation conditions for fermented green jujube wine and its quality analysis during winemaking

Functional Nutrients and Jujube-Based Processed Products in Ziziphus jujuba

Jujube (Ziziphus jujuba Mill.) is the first tree species in China, with a long history and abundant yield. However, fresh jujubes have a short shelf-life and are not resistant to storage. Therefore, more and more processed jujube products are being studied. These processed products can extend the shelf-life of jujubes and attract widespread attention for their rich functional nutrients. This review summarized changes in nutrients of fresh jujube and processed products and the research progress of different preparation methods of jujubes. Meanwhile, the pharmacological effects of bioactive components in jujube-based products were concluded. Jujube and its processed products contain rich polysaccharides, vitamin C, and other functional nutrients, which are beneficial to humans. As the initial processing method for jujubes, vacuum freezing or microwave drying have become the most commonly used and efficient drying methods. Additionally, processed jujube products cannot be separated from the maximum retention of nutrients and innovation of flavor. Fermentation is the main deep-processing method with broad development potential. In the future, chemical components and toxicological evaluation need to be combined with research to bring consumers higher quality functional jujube products and ensure the sustainable development of the jujube industry.

Optimization of fermentation conditions and quality evaluation of Chaenomeles sinensis glutinous rice wine

The present study was conducted to optimize fermentation conditions for preparation of Chaenomeles sinensis Glutinous Rice Wine (CRW). The dynamic changes of main substances in the liquor during fermentation process, aroma components, biologically active substances and antioxidant capacity in the CRW after 6 months of aging were tested. The results showed that under optimized conditions, the yield and alcohol content of wine was 44.97 and 20.00%, respectively. After aging, 64 aroma components were detected in the wine, mainly alcohols and esters. The alcohol content of the CRW was 14.8%. Polyphenols and flavonoids reached 0.23 g/L and 0.037 g/L respectively. Furthermore, the CRW had an excellent free radical scavenging ability.

Supplementary Information

The online version contains supplementary material available at 10.1007/s13197-024-05934-0.

Optimization of the Process for Green Jujube Vinegar and Organic Acid and Volatile Compound Analysis during Brewing

Healthy fruit vinegar has become very popular recently in China. This study aimed to produce fruit vinegar with a good taste, high nutritional value, and strong functional properties from green jujube. This study investigated the optimization of the process for green jujube vinegar using response surface methodology. The optimum fermentation parameters for green jujube vinegar were determined as follows: initial alcoholicity 6%, acetobacter 8%, fermentation temperature 32 °C, and time 7 d. The organic acids of the optimized sample were evaluated by HPLC, and the volatile substances were identified and analyzed by HS-SPME and GC-MS during the fermentation and aging of the green jujube vinegar. The results showed that the variation trends of the different organic acids during the making of the green jujube vinegar were significantly different. Organic acids are the key flavor compounds of green jujube vinegar, and their changes were mainly attributed to microbial metabolism. In particular, the green jujube vinegar stood out in terms of volatile aroma compounds, including a total of 61 volatile compounds whose major components were acetic acid, isoamyl acetate, ethyl acetate, 3-hydroxy-2-butanone, methyl palmitate, and ethanol. The results can provide theoretical support for the production of green jujube vinegar.

Trends in functional beverages: Functional ingredients, processing technologies, stability, health benefits, and consumer perspective

The World Health Organization's emphasis on the health benefits of functional foods and beverages that has contributed to the rise in its popularity globally. Besides these consumers have become more aware of the importance of their food composition and nutrition. Among the fastest-growing market segments within the functional food industries, the functional drinks market focuses on fortified beverages or products that are novel with improved bioavailability of bioactive compounds, and their implicated health benefits. The bioactive ingredients in functional beverages include phenolic compounds, minerals, vitamins, amino acids, peptides, unsaturated fatty acids, etc. which can be obtained from plant, animal and microorganisms. The types of functional beverages which are globally intensifying the markets are pre-/pro-biotics, beauty drinks, cognitive and immune system enhancers, energy and sports drink produced via several thermal and non-thermal processes. Researchers are focusing on improving the stability of the active compounds by encapsulation, emulsion, and high-pressure homogenization techniques to strengthen the positive consumer perspective in functional beverages. However, more research is needed in terms of bioavailability, consumer safety, and sustainability of the process. Hence, product development, storage stability, and sensory properties of these products are vital for consumer acceptance. This review focuses on the recent trends and developments in the functional beverages industry. The review provides a critical discussion on diverse functional ingredients, bioactive sources, production processes, emerging process technologies, improvement in the stability of ingredients and bioactive compounds. This review also outlines the global market and consumer perception of functional beverages with the future perspective and scope.

Characterization of the Pure Black Tea Wine Fermentation Process by Electronic Nose and Tongue-Based Techniques with Nutritional Characteristics

Wine is an alcoholic beverage, consisting of several compounds in various ranges of concentrations. Wine quality is usually assessed by a sensory panel of trained personnel. Electronic tongues (e-tongues) and electronic noses (e-noses) have been established in recent years to assess the quality of beverages and foods. Response surface and electronic analysis tools were used to examine the quality of black tea wine. The results indicated the optimum initial sugar level (25 °Brix), yeast addition (0.5%), and fermentation temperature (25 °C) for Golden Peony black tea wine. The black tea wine produced under these conditions with 14.0% vol alcohol has as an orange-red color, full wine and tea flavor, and mild and mellow taste. The sourness of the wine was most affected by fermentation factors-yeast addition, fermentation temperature, and initial sugar level. Alcohols, aldehydes, ketones, and alkanes contributed to most of the volatile components under the influence of yeast addition and fermentation temperature. In contrast, nitrogen oxides, aromatics, and organic sulfides contributed under the influence of the initial sugar level. This study provided a facilitated strategy for obtaining the optimum black tea wine fermentation process through electronic nose and tongue-based techniques. The analysis of wines requires new technologies able to detect various different compounds simultaneously, providing worldwide information about the sample instead of information about specific compounds.

Optimization of Mopan Persimmon Wine Fermentation with Pectinase and Analysis of Its Mechanism of Action

Due to the high sugar content of Mopan persimmon, which has an annual output of more than 0.5 million tons in China, it can be processed to make fruit wine. In this study, a strain of yeast screened from different persimmon samples was used for persimmon wine fermentation. The optimal conditions of persimmon wine fermentation were determined through single-factor experiments as follows: Yeast addition of 0.08 g/kg; a fermentation temperature of 28 °C; sucrose addition of 18%; and pectinase addition of 0.01%. Under these conditions, the alcohol content of persimmon wine reached 12.9%. The addition of pectinase during persimmon wine fermentation was found to decompose pectin at high speed, reduce the viscosity of the fermentation liquid, increase the dissolved oxygen content in the fermentation liquid, promote the growth and reproduction of yeast, and effectively convert the sugars into alcohol. After fermentation, alcohol, residual sugars, and total phenolic content with or without pectinase treatment were 12.9 and 4.4%, 2.2 and 13.4 g/L, and 738.7 and 302 µg/mL, respectively. Scanning electron microscopy (SEM) results showed that compared with the mash without pectinase treatment, the mash with pectinase had a larger network structure and more pores and yeasts.

Investigation on the effect of thermal sterilization versus non-thermal sterilization on the quality parameters of jujube juice fermented by Lactobacillus plantarum

This study aimed to evaluate the jujube juice treated by four different sterilization treatments as substrates for producing a probiotic beverage fermented by Lactobacillus plantarum (L. plantarum): sterilization by autoclaving (SA at 0.1 MPa,121 °C, and 20 min), pasteurization (PS at 85 °C/30 min), cold plasma sterilization (CPS at 700 W/120 s) and pulsed strong light sterilization (PLS at 1.0 Hz, 600 J, and 10 times), while jujube juice without sterilization treatment used as control (CK). The results showed that the growth ability of L. plantarum in jujube juice was not affected by different sterilization treatments. After SA and PS treatment, the particle size of jujube juice increased by 440.51% and 222.29%, respectively, and the reducing sugar content decreased by 33.83% and 24.51%, respectively. Compared with SA and PS, PLS and CPS were beneficial to improve the stability of jujube juice, and tartaric acid content in jujube juice was significantly increased after CPS treatment. There was no significant difference in sensory and nutritional quality between PLS treated jujube juice and control, and the color of PLS treated jujube juice was significantly better than that of the other three sterilization treatments. The research indicated that PLS treatment could be a prospective sterilization method applied in the processing of fermented jujube juice.

Supplementary Information

The online version contains supplementary material available at 10.1007/s13197-022-05358-8.

The Effect of In Vitro Gastrointestinal Digestion on the Antioxidants, Antioxidant Activity, and Hypolipidemic Activity of Green Jujube Vinegar

Healthy fruit vinegar has been extensively favored in China in recent years. As a new type of fruit vinegar developed by our laboratory, green jujube vinegar has the characteristics of good taste and rich nutrition. To study the effect of in vitro gastrointestinal digestion on the antioxidant and hypolipidemic activity of green jujube vinegar, so as to provide basic data for research and the development of healthy food antioxidants, including the total phenolic content (TPC), total flavonoid content (TFC), total acid content, and volatile acid content, were measured. The antioxidant activity was measured by using 2,2-Diphenyl-1-picrylhydrazyl (DPPH) and 2,2′-Azino-bis(3-ethylbenzthiazoline-6-sulfonic acid) (ABTS) free radical scavenging methods and the ferric reducing antioxidant power assay (FRAP), and the hypolipidemic activity was measured by cholesterol adsorption and the sodium cholate adsorption capacities. The results show that gastric digestion significantly (p < 0.05) decreased the TPC, TFC, total acid content, and volatile acid content, for which the highest reductions were up to 54.17%, 72%, 88.83% and 82.35%, respectively. During intestinal digestion, the TFC remained at a high level and unchanged, and the TFC and volatile acid content significantly (p < 0.05) decreased by 72.66% and 89.05%, respectively. The volatile acid content did not significantly (p > 0.05) change within 2 h. The ABTS free radical scavenging ability and the reducing power free radical scavenging rate were correlated with the TPC, TFC, and total acid contents, and the DPPH free radical scavenging ability and cholesterol adsorption capacity were not. These findings suggest that green jujube vinegar can be a potential functional food for people’s use.