Increases in Phenolic, Fatty Acid, and Phytosterol Contents and Anticancer Activities of Sweet Potato after Fermentation by Lactobacillus acidophilus

Abstract

Phenolic, fatty acid, and phytosterol contents in sweet potato (SP) fermented by Lactobacillus acidophilus were evaluated and compared with those of raw and boiled SPs. The differences in the profiles and levels of phenolics between the raw and boiled SPs were not as significant as the differences between those and the fermented SP. The levels of caffeic acid and 3,5-dicaffeoylquinic acid in fermented SP were more than 4 times higher than those in raw and boiled SPs. Two phenolics, p-coumaric acid and ferulic acid, which were not detected in either raw or boiled SP, were found in fermented SP. The level of each fatty acid or phytosterol increased in fermented SP and decreased in boiled SP. Among the hydrophilic and lipophilic extracts obtained from raw and fermented SPs, the hydrophilic extract of fermented SP exhibited the highest capability of inhibiting cancer-cell PC-12 proliferation. However, each of the extracts had very low cytotoxicities to normal-monkey-kidney-cell growth. The results indicated that SP fermented by L. acidophilus significantly increased free antioxidant-rich phenolics and inhibited cancer-cell-proliferation activity without cytotoxicity to normal cells.

Screening and application of lactic acid bacteria and yeasts with L‐lactic acid‐producing and antioxidant capacity in traditional fermented rice acid

“…In general, rice acid was prepared through the fermentation process involving lactic acid bacteria (LAB) and yeasts. Fermentation is a common food‐processing method that preserves foods and endows them with special flavors (Shen et al., 2018). Previous studies demonstrated that LAB and yeasts had good probiotic properties and produced a variety of compounds such as organic acids, acetaldehyde, methyl alcohols, and esters (Rai et al., 2019; Yadav et al., 2016).…”

“…Therefore, more fermented foods containing more L‐lactic acid should be developed. LAB and yeasts assist in the release and biotransformation of those health‐beneficial compounds via fermentation, increase their bioavailability, and reduce sugar contents in fermented foods (Shen et al., 2018). The fermentation process of rice acid was optimized (Yuan, 2010).…”

Phenolic compounds and antioxidant activity in sweet potato after heat treatment

“…The bioactive compounds in sweet potato roots, such as phenolics (e.g., chlorogenic, caffeic, and dicaffeoylquinic acids), carotenoids, polysaccharides, and peptides, have generated interest in the field of human nutrition and have renewed the interest of researchers in the agro‐food sector . These compounds are directly responsible for a variety of potential health‐promoting effects exerted by sweet potato roots, including antioxidant, immunomodulatory, anticancer / antitumor, antimicrobial, antiulcer, antidiabetic, antiobesity, and hepatoprotective activities …”

“…2 These compounds are directly responsible for a variety of potential health-promoting effects exerted by sweet potato roots, including antioxidant, immunomodulatory, anticancer / antitumor, antimicrobial, antiulcer, antidiabetic, antiobesity, and hepatoprotective activities. [3][4][5][6] Applications of sweet potato have also diversified considerably, and many researchers have focused on the effects of different drying and cooking methods on the nutritional composition and physicochemical properties of sweet potato. 1 For example, Tang et al, 7 compared the effects of different thermal treatments, such as steaming, roasting, and boiling, on the antioxidant activity of sweet potatoes.…”

Changes Over the Fermentation Period in Phenolic Compounds and Antioxidant and Anticancer Activities of Blueberries Fermented by Lactobacillus plantarum

“…Therefore, conversion of these polymer polyphenolic compounds into simpler compounds via enzymatic hydrolysis or fermentation is one strategy to increase the bioavailability of phenolic compounds (Chamorro, Viveros, Alvarez, Vega, & Brenes, , Nie et al., , Oh, Jeong, Velmurugan, Park, & Jeong, ). Lactic acid fermentation of fruits and vegetables produces bioactive compounds that have antibacterial, anticancer, anti‐inflammatory, antioxidant, and antiviral benefits (Bhat et al., , Fessard et al., , Parvez, Malik, Ah Kang, & Kim, , Shen et al., ). In particular, 24 types of Lactobacillus strains with tannase activity, which can improve the bioavailability of plant materials, have been isolated from various types of kimchi, a traditional Korean fermented food (Kwon, Shim, & Lee, ).…”