Investigation of process and product parameters for physico-chemical properties of low Glycemic Index water chestnut and barley flour-based extruded snacks

Abstract

Purpose Keeping in view the diabetes status that has affected about 415 million people globally and is the leading cause of death in many countries along with therising demand for low Glycemic Index (GI) foods, the purpose of this paper is to optimize the extrusion process for the development of low GI snacks from underutilized crops like water chestnut and barley. Design/methodology/approach The extrusion parameters (screw speed and barrel temperature), feed moisture and water chestnut flour, barley flour proportion, were varied and their effects on system and product responses (specific mechanical energy, water absorption index, water solubility index, bulk density, expansion ratio and breaking strength) were studied. Findings All the system and product responses were significantly affected by independent variables. Response surface and regression models were established to determine the responses as function of process variables. Models obtained were highly significant with high coefficient of determination (R2=0.88). The optimum processing conditions obtained by numerical optimization for the development of snacks were 90°C barrel temperature, 300 rpm screw speed, 14 per cent feed moisture and WCF-to-BF ratio as 90:10. Shelf life studies confirmed that the developed snacks can be safely stored in HDPE bags for a period of six months under ambient conditions. Originality/value Water chestnut and barley flour did not blend till date for extrusion cooking. Such snacks shall be a viable food option for diabetic people and can act as laxative due to high fibre and β-glucan content from barley.

Numerical optimization of process parameters of water chestnut flour incorporated corn‐based extrudates: Characterizing physicochemical, nutraceutical, and storage stability of the developed product

“…SME increased with higher screw speed which may be because of the delivery of more energy at higher screw speed, which in turn increases screw shear rate. Our results are in concomitance with the results of Beigh et al (2020). Feed moisture and barrel temperature showed negative impact on SME.…”

“…EI was calculated as the ratio between the thickness of extrudate and die diameter (Beigh et al, 2020). The thickness of the extrudates was determined using a Digital Vernier Calliper of ±0.001-mm accuracy.…”

“…WAI is an index of gelatinization and measures the amount of water absorbed by starch. It depends on the available water binding hydrophilic sites (Beigh et al, 2020). WAI varied from 2.93 to 12.0 g/g (Table 3).…”

“…2.4.1 | Specific mechanical energy SME was calculated as per the below given Equation (2) (Beigh et al, 2020).…”

“…As such, incorporation of different bioactive compounds including dietary fiber, vitamins, and minerals in RTE-extruded snacks has a potential scope for improving their health benefits and consumer acceptance. Various authors have developed snacks using underutilized crops and investigated their bioactive properties (Beigh et al, 2020;Shalabh et al, 2012). Water chestnut is one of the ideal underutilized crops which could be explored for development of healthy snacks.…”