Effect of freeze and vacuum drying on the retention of nutrient content of brown rice (Oryza sativa) porridge

Abstract

Background: Brown rice (BR) is a traditional health food that has high active compounds which have effective preventive and therapeutic effects on many diseases. Brown rice (Oryza sativa) is a healthy grain that has several advantages for infant health compared to white rice. It is one of the healthiest and most researched forms of rice that contains complex carbohydrate giving the feel of satiety and fullness. Due to its high natural nutrition content and fiber content, BR cereal makes the ideal first solid food for infants. Aim: In the current study, the impact of freeze and vacuum drying on the retention of macro and micronutrients was examined. Methods: Freeze drying was carried out at a temperature − 45° ± 5 °C under a vacuum of 10 Pa absolute pressure and vaccum drying was carried out at 40 °C with a vacuum pressure of 76 cm Hg. The proximate composition and micronutrient were analysed as per standard Association of official analytical collaboration (AOAC) methods. Atomic absorption spectroscopy and high-performance liquid chromatography were used to determine the minerals and vitamins in the products and samples. Results: The micronutrient content of the freeze-dried sample was found to contain 42.87 ± 0.13 mg/100 g of potassium, 6.6 ± 0.10 mg/100 g of sodium, 1.39 ± 0.02 mg/100 g of iron, 1.25 ± 0.01 of zinc, and 0.45 ± 0.02 mg/100 g of vitamin B6, whereas the micronutrient content of vacuum-dried powder contains 40.21 ± 0.09 mg/100 g of potassium, 6.4 ± 0.11 mg/100 g of sodium, 1.25 ± 0.01 mg/100 g of iron, 1.08 ± 0.02 of zinc, and 0.42 ± 0.02 mg/100 g of vitamin B6. Conclusion: The results showed that retention of micronutrients in brown rice porridge was high in freeze drying compared to vacuum drying.