Physicochemical properties, in vitro digestibility and structural attributes of okara‐enriched functional pasta

Abstract

Soy okara is a by‐product of soybean processing which offers immense potential to be incorporated into the diverse food products due to its high nutritional and biological significance. The current research aimed to examine the impact of varying soy okara contents (10%–50%) on physicochemical attributes, in vitro protein digestibility, and glycaemic index (GI) of microwave processed durum wheat semolina pasta. Total phenolic content and antioxidant activity improved when 50% of soy okara was added (158.37 ± 0.40 to 232.90 ± 0.85 mg GAE/100 g and 10.87 ± 0.10%–56.21 ± 0.05%). The GI of enriched samples was significantly lower than control pasta (27.41 ± 0.05–12.38 ± 0.01). Fourier transfer infrared spectroscopy revealed no structural changes between control and soy okara‐fortified pasta. Studies indicated that pasta enriched with soy okara has the potential to be commercialized on the industrial level to develop nutritional enriched functional pasta. Practical applications Current research reports the effect of incorporation of soy okara on physicochemical properties, in vitro digestibility, and structural attributes of functional pasta. Enriched pasta showed an improved antioxidant profile with the satisfactory organoleptic score. Hypoglycaemic effect of enriched pasta suggested that soy okara could be used to make the functional pasta which has potential to provide various health benefits. Findings of this work will promote the effective utilization of soy okara in pasta formulation with a high level of protein and fiber.

Bioactive components, in vitro digestibility, microstructure and application of soybean residue (okara): a review

“…It has been stated that β‐glycosidic bonding is a main structural feature of immunostimulatory and antitumor effects. Kamble et al () also confirmed the existence of transmittance bands at 1,010, 1,529, 1,696, 2,362, 2,931, 3,635, 3,745, and 3,846 cm −1 regions in pasta formed with okara flour integration. The observed transmittance peak at 1,010 cm −1 may be correlated with the amorphous state of starch granules resulting from the C─O─ stretching vibration (Bashir & Aggarwal, ).…”

“…The structural study of okara flour was previously investigated using various techniques, including scanning electron microscopy (SEM; Porcel et al, ; Voss et al, ; Santos et al, ) and Fourier transform infrared (FTIR) spectroscopy (Kamble et al, ; Li et al, ; Quintana, Gerbino, & Gómez‐Zavaglia, ). SEM is a useful technique for determining the microstructure of food products by evaluating the arrangement of starch granules within the protein matrix (Kamble et al, ). Santos et al () conducted a study to examine the microstructure of okara flour particles by means of an SEM (Figure ).…”

“…The chemical nature of starch, particularly the amylose and amylopectin material, is another factor affecting their digestibility (Hibberd et al, 1982). Protein digestibility is an important indicator while assessing the quality of the protein source (Kamble et al, ). The protein digestibility of a food is known as the proportion of nitrogen in a food that is consumed after digestion.…”

“…Okara can partially replace wheat flour, soy flour, and other food‐producing components in order to boost the fiber and protein content (Li et al, ). The use of okara in different food formulations has been investigated earlier (Genta, Genta, Alvarez, & Santana, ; Kamble et al, ; Kang et al, ; Katayama & Wilson, ; Khare, Jha, & Sinha, ; Pan, Liu, & Shiau, ; Park et al, ; Waliszewski, Pardio, & Carreon, ; Wickramarathna & Arampath, ).…”

“…The results indicated that 5–10% okara powder and 6% vital wheat gluten addition produces noodles with good cooking, texture, and sensory properties. Kamble et al () studied the physicochemical attributes, IVPD, and GI of microwave‐processed pasta made by replacement of durum wheat with various levels of okara flour (10–50%). The results indicated that total phenolic content (158.37 to 232.90 mg GAE/100 g) and antioxidant activity (10.87 to 56.21%) improved significantly by replacement of okara up to 50% level.…”