Effects of soaking and grinding conditions on anti-nutrient and nutrient contents of soy milk

Abstract

Although soy milk is a very good source of nutrient with high biological value, the presence of anti-nutritional factors affects its nutrition quality and limits bioavailability of the nutrients. The effects of soaking duration and combination of soaking and grinding (hot or cold) on phytate, lipoxygenase, urease, trypsin inhibitor activity, protein solubility and other nutrient contents were investigated. Soaking alone at 55 and 60oC for different durations was found effective for the reduction of lipoxygense activity. Combination of soaking, blanching (80oC for 10 min) and hot grinding (100oC) significantly (P>0.05) reduced urease activity, more than 80% phytate activity and deactivated trypsin inhibitor, but did not affect protein solubility. Meanwhile, protein solubility (10–15%) was increased due to hot grinding. Soy milk extracted from soaking at 55 and 60oC for 2, 4 and 6 h with hot grinding provided higher protein content compared to cold grinding. Increase in soaking temperature from 55 to 60oC increased the extracted solid content having a potential fraction of lipid. Increasing soaking time from 4 to 6 h did not show any significant difference in terms of phytate inhibition, urease activity reduction, trypsin inhibition and protein solubility except lipoxygenase activity. The results suggested that soaking of soybean at 60oC for 6 h and hot grinding (100oC) with blanching at 80oC for 10 min is the best for reducing anti-nutrient and retaining nutrient activity for soy milk and other soy-based products.J. Bangladesh Agril. Univ. 16(1): 158-163, April 2018

Nutritional, textural, and sensory quality of oil fried donut enriched with extracted dietary fiber and okara flour

“…The blanched soybeans were ground with the addition of hot water (100°C) at a ratio of 4:1 (water: soybean) using a super mass colloider (Masuko Sangyo Co. Ltd., Kawaguchi, Japan) (Nowshin et al, 2018). Soy okara was collected after soy milk extraction using disk centrifuge and filtering through double layer cheese cloth.…”

“…Kamble et al (2019) found that reduced IVPD of okara-enriched pasta might be due to the presence of high levels of dietary trypsin inhibitors and other anti-nutrients in okara flour that reduced IVPD by inhibiting the action of proteolytic enzymes. However, heat treatment can reduce the anti-nutrient in soybean and soybean products and increase the protein digestibility (Nowshin et al, 2018).…”

Alternative protein source: Acceptability of cow blood meal in place of fish meal assessed via growth, antioxidant enzymes functions and haematological response inClarias gariepinus(Burchell, 1822)

“…However, the FM content in the control diet was 45% while CBM was 0%. Soybean used for diet formulation was toasted (Ogunji, 2004), before grinding to lessen antinutritional factors (Iheanacho et al, 2019; Nowshin et al, 2018).…”

Recent innovations in processing technologies for improvement of nutritional quality of soymilk

“…The combination of soaking (60°C for 6 h), blanching (80°C for 10 min), and hot grinding (100°C) inactivated about 27% of phytate in soymilk. When soaking soybeans at 55°C or 60°C for 4 h under the same blanching and grinding conditions, greater levels of total solids (7.65-8.36%) and protein (4.46-5.67%) were yielded than those of cold grinding (6.37-6.55% for total solids and 4.02-4.13% for protein) (p < .05) (Nowshin et al, 2018). Soymilk from roasted soybeans at 110°C for 20-80 min and 120°C for 20 min retained a comparable protein content (3.1-3.6%) to raw soymilk (3.4%) (Navicha et al, 2017).…”