EFFECTS OF STORAGE CONDITION, PREPARATION AND HEAT TREATMENT ON SOME GROUP B VITAMINS IN Sauropus androgynous

Abstract

Rau ngót or Bồ ngót is a kind of green leafy vegetable in Vietnam with the scientific name Sauropus androgynous. The fresh leaves contained protein, lipid, ash, and fiber levels of (24.05±0.87); (4.20±0.02); (8.74±0.24); and (7.21±1.19) % dry weight (DW), respectively. The research aimed to determine the impact of the storage conditions (when stored in polythene bags at temperatures of 6.20±2.89 °C and moisture 49±13.23 %) and method preparation (crushing and not crushing the leaves) before thermal processing on the change vitamin B group leaf content. According to the study using High-Performance Liquid Chromatography (HPLC) analysis, except for vitamin B₃, most of vitamin B group of the leaves tend to lose roughly 50 % of their weight after eight days in the refrigerator. Vitamin B₃ increased significantly after two days of storage (123.39±19.45 mg/100g DW versus 203.75±3.94 mg/100g DW), then decreased slightly after every two days. All plant leaves were heated directly in water at a temperature of 90–100 °C for 15 minutes, with two ways of pretreatment: rub and non-rub. All of the vitamins tested were reduced, although there were no significant variations between samples when treated in two different ways before thermal processing.