Journal of Nutrition & Food Sciences
Open Access

Abstract

Changes in Macronutrient, Total Phenolic and Anti-Nutrient Contents during Preparation of Tempeh

Hasnah Haron and Norfasihah Raob

Background: The effects of processing towards changes in contents of macronutrient, total phenolic and antinutrient during preparation tempeh was studied. Tempeh preparation was carried out using the usual method used in the tempeh cottage industry in Malaysia. Methods: The samples studied were in the form of raw, soaked, cooked soya bean and tempeh. Macronutrients, total dietary fiber (TDF), total phenolic, phytate and oxalate were determined using AOAC method, Folin-Ciocalteu assay, Anion Exchange Column (AEC) and Oxalate kit, respectively. Each analysis was carried out with minimum of four replicates for every sample. Results: Raw soya bean contained significantly lower (p<0.05) content of moisture (10.11%) but highest in ash (5.27%), protein (32.80%), fat (10.60%), carbohydrate (41.22%), phytate (615.00 mg/100 g) and oxalate (43.43 mg/100 g) contents when compared to tempeh. Phenolic content (8.90 mg GAE/100 g) increased significantly after fermentation process and it was not significantly different compared to the one in raw soya bean. Fermentation process also caused increment moisture content but reduction in ash, protein, fat, carbohydrate, phytate and oxalate contents in tempeh. Conclusions: Nutrient and phenolic contents reduced after soaking and boiling process. However, total phenolic increased after fermentation process. Anti nutrients like phytate and oxalate contents were reduced significantly with fermentation. Tempeh produced in this study can be considered as food containing low amount of oxalate content (<10 mg/ serving).