Effects of Transglutaminase on the Protein Network and In Vitro Starch Digestibility of Asian Wheat Noodles

Abstract

Wheat noodles are a staple commonly consumed in Asia, but high intakes have been associated with type 2 diabetes due to its rapid starch digestibility. We hypothesised that protein network-binding via transglutaminase (TG) would form a stronger barrier encapsulating the starch granules to limit enzymatic access and digestion. The amount of glucose release decreased significantly with increasing TG concentration, with a reduction of approximately 16% with 2% TG after 120 min of digestion. The slower rate of glucose release during the first 60 min of digestion for 2% compared to 0% TG suggested impeded first stage enzymatic access rather than second stage starch hydrolysis into glucose. Upon increasing the TG concentration, confocal microscopy revealed a denser protein network with increased connectivity, supported by a decrease in protein solubility and gelatinisation enthalpy, and increased firmness and work of shear. Therefore, transglutaminase can potentially be used to reduce starch digestibility in wheat noodles via protein network-binding.

Applications of protein crosslinking in food products

“…TG in the concentration of 3 and 4% activated protein crosslinking and increased cooking yield, hardness, and tensile strength, while decreasing cooking loss and adhesiveness of alkaline rice noodle (Gharibzahedi et al, 2019). Upon increasing TG concentration in wheat noodles, a denser protein network with increased connectivity, supported by a decrease in protein solubility and gelatinisation enthalpy, and increased firmness and work of shear were observed (Wee and Jeyakumar Henry, 2019). Kumar et al (2019) reported that the combination of sodium caseinate, whey protein concentrate, and TG decreased the cooking loss, water absorption, and pasting properties, but increased L*, a*, b* and sensory attributes of gluten-free pasta.…”

Starch‐based noodles: Current technologies, properties, and challenges

“…Ge et al (2022) reported that the addition of konjac glucomannan (0–50 g/kg) to the salted (2%) wheat flour‐based noodles reduced the T p and ∆ H values during the storage duration (1–60 days, under the ambient temperature) where they observed the values of T o (37.58–50.56°C), T p (52.48–60.32°C), T c (66.85–73.02°C), and Δ H (0.55–1.36 J/g). Wee and Henry (2019) developed noodles consisting of Asian wheat flour, transglutaminase enzyme powder (0–2%), and salt (1%) as components and observed the increased values of T o (56.7–60.0°C) and ∆ H (3.4–5.4 J/g) with increasing the enzyme concentration where the values of T p and T c ranged between 65.4–66.3°C and 72.4–73.6°C. Tian et al (2021) confirmed the increased △ H value of the starch in rice (Ningchun 4 variety) flour‐baes white‐salted noodles than that stored at 4°C where the observed thermal properties of the noodles are T o (49.75–74.31°C), T p (58.15–82.35°C), T c (66.07–88.73°C), and △ H (0.25–4.55 J/g).…”

Modulation of fried spring roll wrapper quality upon treatment of batter with maltogenic amylase, transglutaminase and bromelain

“…11 TG catalyzes the acyl transfer reaction between lysine and glutamine to form a stable protein network. 12 Bromelain (BRO) is capable of hydrolyzing proteins into small molecules of peptides and amino acids. 13 Given the vital role of protein and starch in batters in affecting the oil contents and the quality of FRSW, as well as the characterics of MA, TG and BRO on the modification of protein and starch, it was hypothesized that MA, TG and BRO would have a significant impact on the batter and the quality of FRSW.…”