Gluten-free starch noodles from sweet potato with reduced starch digestibility and enhanced protein content

Abstract

Sweet potato starch (SPS) noodles despite being gluten-free, has low nutritional value as it lacks proteins, minerals, vitamins etc. The objective of this study was to develop gluten-free starch noodles from sweet potato with enhanced protein content through fortification with whey protein concentrate (WPC) and to study the effect of protein fortification and blending SPS with banana (BS), cassava (CS) and mung bean (MBS) starches and annealed cassava starch (ACS) in reducing the starch digestibility. The highest protein retention in cooked noodles was obtained for 20 % WPC fortification, while the lowest starch digestibility was observed for 40 % BS fortified noodles followed by 50 % ACS fortified noodles. The highest resistant starch (RS) retention was for BS and ACS fortified noodles, which also had medium glycemic index of 66.3 (BS) and 67.2 (ACS). High sensory scores were obtained for the BS and 20 % WPC fortified noodles. The study showed that protein and/or BS fortification with SPS could enhance the acceptability as well as functional value of SPS noodles.

Physicochemical and functional properties of sweetpotato flour

“…The starch granules are broken down by heating, which allow amylose and amylopectin to be more readily digested by the enzymes. Although SPF has a high GI as shown in this study, noodles with sweetpotato starch have a medium GI of 66.3, which were ideal for patients suffering from obesity and type 2 diabetes . The difference suggests the importance of food matrix effect.…”

“…Cereals containing gluten may cause food allergy and coeliac disease. SPF has been widely used as an ingredient to formulate gluten‐free food products . For example, rice‐sweetpotato pancakes with 20–40% SPF incorporation showed a flow behavior more like that of the traditional pancakes .…”

“…SPF has been widely used as an ingredient to formulate gluten-free food products. 28,31 For example, rice-sweetpotato pancakes with 20-40% SPF incorporation showed a flow behavior more like that of the traditional pancakes. 31 SPF is also a good source of bioactive compounds such as -carotene from OS and anthocyanins from PD ( Table 2).…”

“…Although SPF has a high GI as shown in this study, noodles with sweetpotato starch have a medium GI of 66.3, which were ideal for patients suffering from obesity and type 2 diabetes. 28 The difference suggests the importance of food matrix effect. Noodles are tightly packed in a food matrix (strand).…”

Reducing the glycaemic index and increasing the slowly digestible starch content in gluten‐free cereal‐based foods: a review

“…In GF breads, the inclusion (20% w/w) of an RS preparation (RS content of 48.5% dry weight) obtained from HA corn starch subjected to three autoclaving‐cooling cycles markedly increased the RS fraction (7.6% dry weight) and decreased in the in vitro GI values (78, using white bread as reference) with respect to control GF bread (RS level of 1.2% dry weight and in vitro GI value of 97) (Giuberti et al ., ) (Table ). Similar results have been reported using annealed cassava starch (inclusion level of 45%) in GF noodles, where a twice‐higher RS level (30.7% on dry weight) and a lower in vitro GI (about 70 using white bread as reference) have been measured in substituted noodles when compared to control samples (Menon et al ., ) (Table ).…”