Effect Of Moist And Dry Heat Processing Methods On The Nutritional Value Of Mungbean (Vigna Riadiata)

ABSTRACT

A study was conducted to evaluate the nutritional value of mungbean (Vigna radiata), processed in different methods. Treatments consisted of diets formulated with mungbean prepared in three different methods namely raw mungbean diet (RMD), Toasted mungbean diet (TMiD) and boiled mungbean (BMD). The mungbean served as major protein source fed to 21 days old albino rats for biological assay with two other treatments consisting of nitrogen free diet (NFD) and casein diet which served as a control. There were five rats for each of the five different diets, and they were fed for twenty-eight days for biological evaluation. The proximate, mineral and anti-nutritional compositions were determined using appropriate methods. The different diets were also analyzed for the determination of their nutrient components. The result showed that raw mungbean contains 22.76% protein, 130mg/bOg calcium, and 2.76mg/bOg zinc and 4.22mg/bOg iron. The anti-nutritional compounds found include saponin, 0.64%, tannin 0.74%, oxalate 1.25% phytate 2.35% and alkaloids 0.85%. Although minor loss in nutrients was observed on processing, it nevertheless generally improved the nutritional value of mungbean by reducing the anti-nutritional compounds. The protein efficiency ratio (PER) of mungbean diet was reduced on cooking from 1.72 in the raw mungbean to 1.42 and 1.40 for boiled and toasted mungbean diet respectively. On the contrary boiled and toasted mungbean diets resulted in some improvement in the net protein utilization (NPU), true digestibility (TD) and biological value (By). The biological value of mungbean diets ranged from 57.94% for the raw, to 59.23% for the toasted and 60.65% for the boiled respectively, representing 12.2%, 10.2% and 8% less than the casein diet. Boiled mungbean therefore proved more efficient in improving the nutritional value than toasted and raw. The true digestibility (TD) of the test diet significantly differs from one another at (P?0.05) with casein diet> BMD > TMD> RMD. Boiled mungbean can serve as a valuable protein source for people with delicate digestive system, the children and the invalid, as it contains lesser anti-nutritional factors.