Effect of Chemical Soaking, Toasting and Crude α-Galactosidase Enzyme Treatment on the Oligosaccharide Content of Red Gram Flour

Abstract

The effects of soaking in 1 and 2% sodium bicarbonate solution, toasting, roasting followed by boiling and crude a-galactosidase treatment on the levels of the raffinose family of sugars in red gram (Cajanus cajan, L) seeds were investigated. The percent removal of raffinose (43.05 and 73.80%), stachyose (15.80 and 70.27%) and verbascose (18.07 and 51.71%) after soaking in 1 and 2% of sodium bicarbonate solution of red gram seeds for 16 h, respectively. Roasting of red gram seeds for 20 min led to a mean reduction of 64.17% for raffinose, 61.67% for stachyose and 57.53% for verbascose and toasting followed by boiling led to a mean reduction of 19.80% for raffinose, 33.20 for stachyose and 45.58% for verbascose, respectively. The treatment of red gram flour with partially purified agalactosidase from Aspergillus niger for 3 h was effective in reducing the levels of the raffinose family of sugars. PRACTICAL APPLICATIONSThe processing methods such as soaking in sodium bicarbonate solution (1 and 2%) toasting, roasting followed by boiling and crude a-galactosidase from Aspergillus niger treatment are employed to reduce the flatulence inducing raffinose family sugars in legume. Effect of soaking in 2% sodium bicarbonate solution for 16 h led to highest reduction of raffinose family sugars than that of soaking in 1% sodium bicarbonate solution. Toasting of red gram seeds for 20 min has been found to moderate reduction of raffinose family sugars. Roasting for 5 min followed by 20 min boiling found to be low levels of reduction of raffinose family sugars. Whereas the partially purified a-galactosidase from A. niger was effective in reducing the levels of the raffinose family of sugars in all the cultivars studied. Enzymatic treatment for 3 h completely removed the flatus-inducing factors, as evidenced by TLC analysis. This information could further stimulate application of these inexpensive and easy methods for the removal of raffinose family of sugars in different varieties of legume seeds.

Thermal and enzymatic treatments reduced α‐galactooligosaccharides in common bean ( Phaseolus vulgaris L.) flour

“…Particularly, the bSCEf treatment presented a reduction of 97.6% for black and 88.8% for pinto bean (Figure 3A,B). These results are consistent with those reported by Devindra and Aruna (2017), who used a partially purified α-galactosidase from A. niger and completely removed the α-GOS from red gram (Cajanus cajan L) flour. Singh and Kayastha (2013) were able to reduce the α-GOS content from soybean flour, specifically 80.0% of raffinose and 85.0% of stachyose, using a Cicer α-galactosidase purified from white chickpea.…”

Pulse‐based snacks as functional foods: Processing challenges and biological potential

“…This technique consists of immersing the food in edible oil or fat above the boiling water temperature (Liberty et al, 2019). Heat is transferred from the oil to the food, resulting in water evaporation, oil absorption, and crusting (Debnath et al, 2003). Besides increasing shelf life by reducing the moisture content, deep-fat frying provides a smooth and moist interior along with a crispy crust and aroma that improves the palatability.…”

“…Even though α‐GOS may confer health benefits, unpleasant effects could affect the acceptability of these snacks. Various methods have been proposed to reduce the α‐GOS levels in pulses, particularly soaking, cooking, and autoclaving (Devindra & Aruna, 2017; Thirunathan & Manickavasagan, 2018). Dehulling would not reduce the concentration of α‐GOS because they are mainly located in the cotyledons (Moussou et al., 2017).…”

Sustainable Strategies for Increasing Legume Consumption: Culinary and Educational Approaches

“…With enzyme treatment, the enzyme alpha-galactosidase is synthesized and added directly to the whole bean or flour, followed by an incubation phase to increase enzyme activity. In one study, the purified enzyme obtained from Aspergillus niger was used to treat a Cajun bean flour, revealing the complete removal of raffinose, stachyose, and verbascose after treatment [103]. Similar results were obtained on the same type of legume in another study [97].…”