Enhancement of nutritional, sensory and storage stability by lactic fermentation of Auricularia auricula

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.

Effect of microwave-puffed on Auricularia auricula polysaccharide and probiotic fermentation on its biotransformation and quality characteristics during storage period

In this study, probiotics with superior fermentation performance were screened, and the mixed-bacteria fermentation was carried out with Auricularia auricula treated with microwave-puffed process as fermentation substrate, and the changes in nutritional quality under different storage conditions were investigated. The results showed that the acid and bile salt resistance of Lactiplantibacillus plantarum 21,801 and 21,805 reached 95 % and 75 % respectively, and the intestinal adhesion was superior; microwave puffing treatment had the highest retention rate of A. auricula polysaccharides and the lowest loss of polyphenols, and no effect on soluble protein. Mixed bacterial fermentation significantly increased the total polyphenols and total flavonoids of A. auricula (p < 0.05), and the DPPH and ABTS radical scavenging reached 48.31 % and 73.21 % respectively. Furthermore, the viable counts, DPPH radical scavenging, color, and sensory quality of fermented A. auricula remained stable when stored at 4 °C. In contrast, when stored at 25 °C for 7 days, the taste was unfavorable, undesirable odor and spoilage occurred; by 21 days, DPPH clearance rate dropped below 40 % and color changed significantly (△E > 2). In conclusion, the probiotic mixed fermentation and storage conditions had a significant effect on the biometabolic transformation of macromolecules and other substances in A. auricula.

Non-volatile and volatile compound changes in blueberry juice inoculated with different lactic acid bacteria strains

BACKGROUND

Lactic acid bacteria (LABs) are widely present in foods and affect the flavour of fermented cultures. This study investigates the effects of fermentation with Lactobacillus acidophilus JYLA-16 (La), Lactobacillus plantarum JYLP-375 (Lp), and Lactobacillus rhamnosus JYLR-005 (Lr) on the flavour profile of blueberry juice.

RESULTS

This study showed that all LABs strains preferentially used glucose rather than fructose as the carbon source during fermentation. Lactic acid was the main fermentation product, reaching 7.76 g L-1 in La-fermented blueberry juice, 5.86 g L-1 in Lp-fermented blueberry juice, and 6.41 g L-1 in Lr-fermented blueberry juice. These strains extensively metabolized quinic acid, whereas oxalic acid metabolism was almost unaffected. Sixty-four volatile compounds were identified using gas chromatography-ion mobility spectrometry (GC-IMS). All fermented blueberry juices exhibited decreased aldehyde levels. Furthermore, fermentation with La was dominated by alcohols, Lp was dominated by esters, and Lr was dominated by ketones. Linear discriminant analysis of the electronic nose and principal component analysis of the GC-IMS data effectively differentiated between unfermented and fermented blueberry juices.

CONCLUSION

This study informs LABs selection for producing desirable flavours in fermented blueberry juice and provides a theoretical framework for flavour detection. © 2023 Society of Chemical Industry.

The Current State and Future Prospects of Auricularia auricula's Polysaccharide Processing Technology Portfolio

Auricularia auricula polysaccharides (AAP) have been widely studied in the field of medicine and healthcare because of their unique structure and physiological activity. Many species of Auricularia auricula polysaccharides have been extracted, isolated, and purified by different methods, and their structures have been analyzed. Auricularia auricula polysaccharides have been proven to have beneficial effects on the human body, including slowing the aging process, controlling the intestinal system, and treating cardiovascular disorders. In this paper, the extraction, isolation, and purification of AAP from Auricularia auricula, as well as research in the field of medicine and healthcare, have pointed to the shortcomings and limitations of these methods. We also suggest future research directions for Auricularia auricula polysaccharides; standardized processing methods must be confirmed, and officially approved AAPs are needed for commercial applications. Finally, an optimistic outlook on the development of AAPs is given.