Key Factor Underlying Protein Loss Resistance During Heat Cooking in Hom Mali Rice Grown in a Brackish Water Region of Thailand Compared to Rice from Other Cultivation Areas
Abstract
Variations in cultivation conditions influence the nutrient composition of rice and may enhance its tolerance to protein loss during processing. This study compared key factors such as nutritional composition, mineral and amino acid content, bioactive compounds, and cooking quality of Hom Mali rice grown in three regions of Thailand: a brackish water region (BW), a mountainous region (MT), and the Northeast plateau (NP). The effects of these factors on protein loss during different heat-based cooking methods, including baking, pan-frying, and boiling, were evaluated. Rice from the BW region contained higher protein (7%), lower fat (2%), and greater mineral content, including potassium (3,757 mg/kg), magnesium (942 mg/kg), calcium (190 mg/kg), iron (114 mg/kg), and manganese (33.4 mg/kg), compared to rice from MT and NP regions. These minerals were associated with higher levels of bioactive compounds and antioxidant activity. Alanine and valine, amino acids linked to heat resistance, were also more abundant in BW rice. During baking, BW rice showed the lowest protein loss at 2.98%, while MT and NP rice lost 7.81% and 10.4%, respectively. Frying and boiling resulted in even greater losses. These findings highlight the potential of nutrient-rich rice from brackish regions for producing functional, heat-stable food products.
