Improving Phenolic Bioactive-Linked Functional Qualities of Sweet Potatoes Using Beneficial Lactic Acid Bacteria-Based Biotransformation Strategy

Abstract

Beneficial lactic acid bacteria (LAB) based fermentation is an effective biotransformation strategy to preserve and improve the human health-supporting functional qualities of plant-based food substrates. In this study, a food grade strain of Lactiplantibacillus plantarum was recruited to improve the retention, stability, and bioavailability of phenolic bioactives to enhance the antioxidant, anti-hyperglycemic, and anti-hypertensive functional qualities of three flesh-colored sweet potato varieties, Murasaki (off-white-fleshed), Evangeline (orange-fleshed), and NIC-413 (purple-fleshed). Liquid (cold water) extracts of the sweet potatoes, which are relevant for food grade applications, were fermented for 72 h at 37 °C. Total soluble phenolic content, phenolic profile, antioxidant, anti-hyperglycemic, and anti-hypertensive benefits relevant functional properties of fermented and unfermented sweet potato extracts were evaluated at 0, 24, 48, and 72 h time points using in vitro assay models. Overall, high total soluble phenolic content and total antioxidant activity were observed at 24 h, retaining this high level even after 72 h of fermentation. Additionally, moderate to high α-amylase, α-glucosidase, and angiotensin-I-converting enzyme inhibitory activities were observed in the fermented sweet potato extracts. The results suggested that LAB-based fermentation is an effective post-harvest processing strategy for a higher retention of phenolic bioactives and concurrently improves the human health protective bioactive functional qualities of sweet potatoes.

Phenolic Bioactives From Plant-Based Foods for Glycemic Control

“…Similarly, improvement in antioxidant and anti-hyperglycemic functional properties were also observed in LAB fermented cashew ( Anacardium occidentale ) apple juice ( 135 ). Improvement in phenolic bioactive-linked antioxidant, and anti-hyperglycemic functional qualities were also observed in different flesh-colored sweet potato following L. plantarum based fermentation ( 140 ). In recent rat model-based studies, Momordica charantia extracts fermented with L. plantarum showed improvement in lipid metabolism, glycemic control, and beneficial alteration in gut microbiota composition relevant for wider T2D benefits ( 141 , 142 ).…”

Sweet Potato (Ipomoea batatas L.) Phenotypes: From Agroindustry to Health Effects

“…SP is a common staple food in certain middle/low-income countries with great nutritional and functional potential. Its health benefits are not limited to its nutrients but also to other xenobiotics, including resistant starch [ 64 , 65 ], antioxidants [ 19 , 78 , 79 , 80 , 81 , 82 , 83 , 84 , 111 ], terpenoids [ 12 , 88 ], phytosterols [ 96 , 97 ], bioactive peptides [ 88 , 121 , 122 ] and many other phytochemicals that modulate key metabolic processes, reducing the odds for chronic illnesses including, yet not restricted to certain types of cancer [ 92 , 94 , 96 , 100 , 102 , 103 , 104 , 105 , 106 , 107 , 108 , 109 , 110 ] and CVD. Further research should focus on understanding the physiological mechanisms and metabolic biotransformation of raw/processed SP’s bioactives whose intrinsic functionalities (e.g., anti-inflammatory, antioxidant, enzyme-inhibitory activity) target multiple target organs [ 88 , 89 , 90 ].…”

“…Moreover, it has been demonstrated in hamsters that consuming SP leaves increases the presence of favorable biomarkers to reduce the risks for CVD [ 118 ] by inducing vascular (aortic) relaxation [ 119 ] mediated by nitric oxide (NO) as an inhibitor, in the presence of N ω -nitro-l-arginine (NOLA), an inhibitor nitric oxide synthase (NOS), or by eliminating it from the endothelium [ 120 ]. As for SP root, <3 kDa hydrolyzed peptides (VSAIW, AIWGA, FVIKP, VVMPSTF, and FHDPMLR) from sporomin A and B, display a strong anti-ACE (angiotensin-converting enzyme) activity [ 88 , 121 ], while lactic acid bacteria (LAB)-based fermentation of white (Murasaki), orange (Evangeline) and purple (NIC-413)-fleshed SP varieties increases their anti-ACE/antioxidant activity [ 122 ]. Additional evidence on the cardioprotective effects of extracts of SP and/or its pure phytochemicals previously identified by chromatographic techniques is summarized in Table 5 .…”

Development of low‐fat and anthocyanin‐rich purple sweet potato vacuum fried chips

“…In comparison to conventional frying, vacuum frying studies of various types of vegetables concluded the higher preservation of natural pigments, color, flavors (Shyu & Hwang, 2001), lower acrylamide production (Granda et al., 2004), and negligible unfavorable effect on oil quality (Shyu et al., 1998). Recently, sweet potatoes have gained global recognition as a superfood due to wider diversity in flesh color (white, off‐white, cream, orange, and purple) and high level of nutritional components that can provide several human health benefits like antioxidant, antidiabetic, and antihypertensive properties (Chintha et al., 2021). Among different flesh‐color sweet potatoes, purple flesh sweet potatoes (PSP) are the most abundant sources of natural flavonoids such as anthocyanins with several nutraceutical and pharmaceutical functionalities (Steed & Truong, 2008).…”