Effect of Solid-State Fermentation Tempe Type on Antioxidant and Nutritional Parameters of Buckwheat Groats as Compared with Hydrothermal Processing

Abstract

The effect of fermentation with Rhizopus oligosporus, roasting and cooking on functional parameters and nutritional composition of unroasted buckwheat groats was studied. Tempe showed 57 and 124% higher activity against 2,2′-azinobis(3-ethylbenzothiazoline-6-sulfonic acid) radical cation (ABTS •+ ) than cooked unroasted and roasted groats, respectively. Efficient doses of mg material necessary to scavenge • OH (IC50) and exert reducing power (RP0.5) were decreased in tempe (by 61% and about 30%, respectively, as compared with roasted groats). All the parameters were strongly correlated with the soluble phenol level. Tempe contained more thiamine (2.5-fold) and riboflavin (7.5-fold) than cooked buckwheat. It had 143 g/kg protein of the highest Cys + Met and Tyr + Phe levels. In vitro bioavailability of tempe protein (56%) was higher than cooked unroasted groats (41%) and similar to cooked roasted ones. Sensory analysis of buckwheat tempe was concluded with a good overall assessment. Tempe-type fermentation may be recommended as a favorable technique of unroasted buckwheat groats processing. PRACTICAL APPLICATIONSConventional cooking and/or roasting of buckwheat seeds influences the nutritional composition and partially diminishes the functional parameters of groats. Tempe-type product obtained from unroasted groats is a convenient food of improved parameters that may broaden the gluten-free product spectrum on the market. Fermented buckwheat groats are also a potential source of flour of advantageous antioxidant parameters for application as a food additive.

Effects of Fermented Edible Seeds and Their Products on Human Health: Bioactive Components and Bioactivities

“…Especially, fermentation by fungi and LAB, such as G. frondosa , R. oligosporus , and Lb. acidophilus , has been found to increase thiamin, riboflavin, niacin or pyridoxine in soymilk and buckwheat groats (Zhao and Shah ; Malgorzata and others ; Yang and others ; Starzynska‐Janiszewska and others ). This suggests that some microbes may possess the capacity of producing B group vitamins, consistent with previous studies that some LAB and fungi can synthesize B vitamins (Strzelczyk and Leniarska ; Martens and others ; LeBlanc and others ; Capozzi and others ).…”

Solid-State Fermentation Reduces Phytic Acid Level, Improves the Profile of Myo-inositol Phosphates and Enhances the Availability of Selected Minerals in Flaxseed Oil Cake

“…Rhizopus oligosporus has already been proven to reduce the phytate level during SSF of plant substrates (16). Rhizopus sp.…”

Quinoa Tempe as a Value‐Added Food: Sensory, Nutritional, and Bioactive Parameters of Products from White, Red, and Black Seeds

“…Total protein content (g/kg DM) was estimated in previously mineralized samples on the basis of nitrogen level and multiplied by 6.25 (Marczenko and Balcerzak 1998). Antioxidant parameters and phenolic compounds were determined in acetone/water (1:1, v/v) extracts (Starzyńska-Janiszewska et al 2016). Ash content was determined by using a muffle furnace (type Czylok SM-2002) at 550°C (ICC 1990).…”

“…The content of free amino acids (g/kg DM) was measured with the ninhydrin method in extracts obtained after boiling in 80% ethanol according to the method of Korenman (1973). Antioxidant parameters and phenolic compounds were determined in acetone/water (1:1, v/v) extracts (Starzyńska-Janiszewska et al 2016).…”

“…However, the application of different substrates, namely, other legume seeds or legume-grain mixtures, can result in creating products of unique taste, if the mold strain is properly chosen. Descriptions of good-quality tempe from cereal seeds as well as buckwheat groats can be found in the literature (Berg et al 2007;Starzyńska-Janiszewska et al 2016). Tempe-type products from pseudo-cereals could be of interest because of the increasing demand for gluten-free foods on the market.…”