In this study, the walnut flowers were fermented using five different probiotics, including two Lactobacillus plantarum, one Lactobacillus bulgaricus, one Lactobacillus casei, and one Lactobacillus rhamnosus. The chemical compositions, antioxidant capacities, and α-glucosidase inhibitory abilities of walnut flowers during fermentation processes were evaluated. The results showed that all the active compounds and bioactivities of the walnut flowers were significantly decreased after 7 days of fermentation, whereas a short-term fermentation (1-3 days) enhanced their bioactivities. Compared to the unfermented sample, L. plantarum (ATCC 8014) and L. rhamnosus (ATCC 53013) increased the ABTS (1.22 and 1.30 times higher) and DPPH radical scavenging activities (up to 1.23 and 1.04 times), respectively. L. plantarum (SWFU D16), L. plantarum (ATCC 8014), and L. rhamnosus (ATCC 53013) improved the ferric reducing antioxidant power which was 110.98%, 133.16%, and 104.76% of the unfermented sample. All five probiotics promoted the α-glucosidase inhibitory ability of walnut flowers (maximum 2.18-fold increase). Three phenolic acids and five flavonoids in the fermentation broth were identified by HPLC, where catechin, epicatechin, and catechin gallate were the dominant components. HPLC results demonstrated that these compounds were degraded and transformed in varying degrees under the effects of probiotics. Taken together, a short-term probiotic fermentation could change the active compounds of the walnut flowers and improve their bioactivities. L. plantarum (ATCC 8014) and L. rhamnosus (ATCC 334) are suggested as suitable strains in producing the fermented walnut flowers. The research findings could further support the development and utilization of walnut flowers as a fermented functional food. PRACTICAL APPLICATIONS: Walnut flowers have been used as fermented food in southwestern China, but their active components and functional activities during fermentation processes are still unclear. This study found that different probiotic fermentation exerted a strong and varied influence on the chemical composition and biological activities of the walnut flowers. A short-term fermentation has significantly improved their antioxidant capacities and α-glucosidase inhibitory abilities, whereas the longer period of fermentation, caused a significant loss of both their active compounds and bioactivities. These findings are useful as a reference for the manufacturers of fermented walnut flowers in selecting suitable strains and fermentation time for their products.
The consumption value seems to be insufficient to explain consumers' domestic electric vehicle purchase behaviour, especially in a highly competitive global environment. This study aims to investigate how consumer ethnocentrism and perceived interactivity influence consumption value and pro-environmental value, subsequently affecting attitude and intention. A total of 353 valid questionnaires were collected through convenience sampling in Xuzhou, China, and the partial least square (PLS) path modelling approach was performed to test the hypotheses. The results show that consumer ethnocentrism and perceived interactivity positively influence function value, emotional value, and social value; perceived interactivity also positively influences altruistic value, biospheric value, and collectivistic value. Function value, social value, and collectivistic value positively influence attitude; however, emotional value, altruistic value and biospheric value did not find a correlation with attitude. Furthermore, attitude positively influences intention to adopt domestic electric vehicles. Finally, the theoretical and practical implications, as well as limitations were discussed accordingly.