Phenolics Profile, Antioxidant Activity and Flavor Volatiles of Pear Juice: Influence of Lactic Acid Fermentation Using Three Lactobacillus Strains in Monoculture and Binary Mixture

Abstract

The aim of this study was to evaluate the effects of lactic acid fermentation using three Lactobacillus strains (Lactiplantibacillus plantarum 90, Lactobacillus helveticus 76, and Lacticaseibacillus casei 37) in monoculture and binary mixture on phenolics profile, antioxidant activity and flavor volatiles in pear juice. Results showed that the colony counts of binary mixture were higher than monoculture in fermented pear juice. The total content of phenols was increased, while that of flavonoids was decreased significantly during fermentation (p < 0.05). Antioxidant activities in fermented peer juice including DPPH and ABTS radical scavenging abilities and ferric reducing antioxidant power (FRAP) were significantly improved (p < 0.05). Binary mixture of Lactiplantibacillus plantarum 90 and Lacticaseibacillus casei 37 fermentation exhibited strong DPPH radical scavenging ability, due to the increase in vanillic acid and arbutin contents. Furthermore, lactic acid fermentation improved the formation of alcohols, esters, acids and terpenoids, and reduced the contents of aldehydes and ketones. Thirty new compounds including 15 alcohols, seven esters, five acids, and three terpenoids were observed in fermented pear juice. Hierarchical cluster revealed that flavor volatiles in pear juice were improved dramatically by Lactobacillus strains fermentation, and there were dramatic differences between monoculture and binary mixture.

Physical, chemical, and sensory properties of water kefir produced from Aronia melanocarpa juice and pomace

“…Laureys & De Vuyst (2016) also stated that aldehydes such as hexanal, furfural and benzaldehyde, which they detected before fermentation, were not found in water kefir after fermentation. Alike our results, Wang, Zhang & Lei (2021) determined that ketones and aldehydes reduced in all fermented pear juices. It can be said that the reduction of aldehydes and ketones results from their degradation or oxidation to alcohols or acids by LAB metabolism ( Xu, Bao, Wu, Lao, Hu & Wu, 2019 ).…”

Vitality, fermentation, aroma profile, and digestive tolerance of the newly selected Lactiplantibacillus plantarum and Lacticaseibacillus paracasei in fermented apple juice

“…Thirteen esters were detected in PAJ, and the most dominant of which was 2-methylbutyl acetate, the characteristic substance in fresh apple juice aroma. 2-methylbutyl acetate imparts fruity and sweet aromas to the juice ( 48 ). Other prominent esters in PAJ, such as ethyl butyrate, ethyl 2-methylbutyrate, hexyl acetate, nonyl acetate, and 2-phenylethyl acetate, were almost completely consumed during the fermentation of L. paracasei and L. plantarum .…”

Antioxidative, cytoprotective and whitening activities of fragrant pear fruits at different growth stages

“…With the development of the fruit, Arbutin, Catechin, Chlorogenic acid, Epicatechin, Kaempferol hexoside-dideoxyhexoside, Rutin, Kaempferol-3-O-rutino side, Quercitrin, Quercetin rhamnoside, Isorhamnetin-3-O-rutinoside, Kaempferol-3-O-glucoside, Isorhamnetin-3-O-glucoside, Kaempferol-3-acetylglucoside, Isorhamne tin-3-acetylhexoside were detected in the four pear fruit species (Figure 3), the 14 phenolic compounds were highest in the young fruit growing stage (5/25-6/22), among which arbutin and chlorogenic acid were the main components of pear fruit phenolics, and arbutin was the highest, in line with the trend for total phenols and total flavonoids. Wang et al (19) also found the highest levels of arbutin and chlorogenic acid in a study of 10 pear varieties, and Zhang and Liu (27) used Yali as samples and also demonstrated that arbutin and chlorogenic acid are the main phenolic substances in pear fruit. In the young fruit stage, the highest arbutin and chlorogenic acid content was found in the Nanguo pear and the Aksu Juju pear, which were 14104.22 µg/g DW, 22403.53 µg/g DW and 10614.57 µg/g DW, 6761.10 µg/g DW, followed by 8,281.87 µg/g DW and 3,816.91 µg/g DW for the Luntai Juju pear, and the lowest 5,663.91 µg/g DW and 2013.04 µg/g DW for the Hongxiang pear.…”

“…These pear fruits are sweet and juicy, fragrant and refreshing, crispy and less residue, and rich in phenolic substances with strong antioxidant activity, such as chlorogenic acid, rutin, epicatechin, catechin, etc. consumer favorite (19). The antioxidative and anti-melanin deposition effects of fragrant pear provide a good pharmacodynamic basis for the research and development of antioxidative and whitening cosmetic products.…”