Lactic acid fermentation of anthocyanin‐rich sweet potato (Ipomoea batatas L.) into lacto‐juice

Abstract

Sweet potato (SP) is an important root crop grown all over the world and consumed as a vegetable, boiled, baked or often fermented into food and beverages. The grated SP roots [non-boiled and fully boiled (boiled in water at 100°C for 15 min) were treated with 0.05% of commercial pectinase enzyme (Pectinex, Novoenzyme) in order to extract the juice. The fresh juice was inoculated with Lactobacillus plantarum MTCC 1407 culture at 28 ± 2°C for 48 h to produce lacto-juice (LJ). The anova analysis of analytical data revealed that there was significant effect of boiling conditions (fully boiled and non-boiled) on pH [F (1, 4) = 220.5, P < 0.001), TA [F (1, 4) = 78.89, P < 0.01], starch [F (1, 4) = 26.63, P < 0.01), total sugar [F (1, 4) = 61.36, P < 0.01) and anthocyanin [F (1, 4) = 32.86, P < 0.01) but not on reducing sugar [F (1, 4) = 2.48, P = 0.19). Sensory evaluation rated the SP LJ acceptable based on texture, taste, aroma, flavour and after taste. LJ prepared from fully boiled roots with 10% cane sugar was most preferred by a consumer's panelist based on Linear Discriminant Analysis. Principal component analyses (PCA) reduced the seven original analytical variables to three independent components (factors), which accounted for 99.9% of the total variations. Similarly, six original sensory variables were reduced to two independent components, which accounted for 65.7% of the total variations.

Effect of potentially probiotic lactic acid bacteria on the physicochemical composition and acceptance of fermented cereal beverages

“…It was observed that pH was clearly separated from the rest of the physicochemical parameters having a greater relationship with acceptance. These results are comparable to those observed during the PCA assessment of the physiological attributes of sweet potato juices fermented with lactic acid bacteria where pH was also separated from the rest of the parameters (Panda, Naskar, Sivakumar, & Ray, 2009). Furthermore, in previous studies PCA has been successfully applied for the assessment of food products fermented with lactic acid bacteria such as yoghurt and soy products (Jaworska, Waszkiewicz-Robak, Kolanowski, & Swiderski, 2005;Pyo & Song, 2009).…”

Traditional and novel fermented foods and beverages from tropical root and tuber crops: review

“…Enriched with ascorbic acid, phenols, and coloured pigments (b-carotene and anthocyanin) Panda et al, 2009 Yams, taro and cococyams Amala…”

“…In many cases, the most obvious change in LA fermentation is the production of acid and lowering of pH those result in an increase in sourness . Experimental work on pickling of b-carotene and anthocyanin-rich sweet potato by LA fermentation (sauerkraut process) using 5-20% (w ⁄ v) brine solution has been carried out at Regional Centre of CTCRI, Bhubaneswar, India (Panda et al, , 2009. It not only produced LA which imparted taste and flavour to lacto-pickles, but also preserved ascorbic acid, phenols, and coloured pigments (b-carotene and anthocyanin); all these are considered as anti-oxidants (Shivashankara et al, 2004).…”

Sweetpotatoes

“…Sweetpotatoes also used as substrates in soy sauce fermentation (Data et al 1986). Other fermented sweetpotato products rich in carotene and anthocyanins that have been developed in recent years include yogurt (Collins et al 1990), curd (Mohapatra et al, 2007), fermented beverages (Saigusa et al 2005), lacto-pickle (Panda et al 2009a), lacto-juice (Panda et al 2009b) and probiotic milk-sweetpotato drink (Perez and Tan 2006). The application of bioprocessing technology and the progress in the development of fermented products from sweetpotatoes was recently review by Ray et al (2010).…”