Identification of an Invertase With High Specific Activity for Raffinose Hydrolysis and Its Application in Soymilk Treatment

Abstract

The hydrolyzation of raffinose into melibiose by using invertases under mild conditions improves the nutritional value of soybean products. However, this strategy has received little attention because a suitable invertase remains lacking. In this study, a novel invertase named InvDz13 was screened and purified from Microbacterium trichothecenolyticum and characterized. InvDz13 was one of the invertases with the highest specific activity toward raffinose. Specifically, it had a specific activity of 229 U/mg toward raffinose at pH 6.5 and 35°C. InvDz13 retained more than 80% of its maximum activity at pH 5.5–7.5 and 25–40°C and was resistant to or stimulated by most cations that presented in soymilk. In soymilk treated with InvDz13 under mild conditions, melibiose concentration increased from 3.1 ± 0.2 to 6.1 ± 0.1 mM due to raffinose hydrolyzation by InvDz13. Furthermore, the prebiotic property of InvDz13-treated soymilk was investigated via in vitro fermentation by human gut microbiota. Results showed that InvDz13 treatment increased the proportion of the beneficial bacteria Bifidobacterium and Lactobacillus by 1.6- and 3.7-fold, respectively. By contrast, the populations of Escherichia and Collinsella decreased by 1.8- and 11.7-fold, respectively. Thus, our results proved that the enzymatic hydrolysis of raffinose in soymilk with InvDz13 was practicable and might be an alternative approach to improving the nutritional value of soymilk.

Invertase enzyme

“…The invertases used to make soymilk must have a high raffinose activity. (Liu J and Cheng J et al, 2021) [36]…”

Efficient Degradation for Raffinose and Stachyose of a β-D-Fructofuranosidase and Its New Function to Improve Gel Properties of Coagulated Fermented-Soymilk

“…Raffinose and stachyose are the primary concentration of galacto-oligosaccharides in soybean, which are the typical flatus-producing factors that lead to flatulence in the human gut [ 2 ]. The direct hydrolysis of raffinose/stachyose by β-D-fructofuranosidase eliminates these flatulence factors and produces several functional melibiose/mannotriose in soymilk [ 3 ]. Melibiose, a reducing disaccharide, has gained considerable attention since the early 21st century due to its beneficial attributes [ 3 ].…”

“…The direct hydrolysis of raffinose/stachyose by β-D-fructofuranosidase eliminates these flatulence factors and produces several functional melibiose/mannotriose in soymilk [ 3 ]. Melibiose, a reducing disaccharide, has gained considerable attention since the early 21st century due to its beneficial attributes [ 3 ]. It promotes calcium absorption in the intestines, helps to cure atopic dermatitis [ 4 , 5 ], suppresses the Th2 response, inhibits aggregation-mediated neurodegenerative disorders as well as polyglutamine-mediated diseases [ 6 , 7 ], and can be used as a high-value additive in human functional foods and pharmaceuticals to maintain and promote good health [ 8 ].…”

“…Yeasts are the primary producers of β-D-fructofuranosidase [ 10 , 11 ] followed by molds [ 12 , 13 , 14 ] and some bacteria [ 15 , 16 ]. However, most of these commonly used microbial β-D-fructofuranosidases are highly efficient in catalyzing sucrose with limited research conducted on their enzymatic activity towards raffinose or stachyose [ 3 , 17 , 18 , 19 ]. To date, only a few β-D-fructofuranosidases have been identified to possess this unique activity, including those from Microbacterium trichothecenolyticum [ 3 ], Bacillus sp.…”

Comparative studies on intracellular invertase from an hyperproducer (Abagboro yeast) and a commercial yeast (Saccharomyces carlsbergensis)

“…3.2.1.26) from Saccharomyces spp. is a globular protein hydrolase which shows highest a nity and activity for hydrolysis of sucrose, but residual activity can also be observed for substrates such as inulin, stachyose, ra nose and 1-kestose [1,2]. Invertase catalyzes the hydrolysis of sucrose (α-D-glucopyranosyl-β-D-fructofuranoside), by cleaving the α-1-β2-glycosidic linkage releasing glucose and fructose in equal amounts known as invert sugar.…”