Development and quality evaluation of soy-walnut milk drinks

Beverages are used to quench thirst, and are taking with snacks as lunch in some countries. In many developing countries, beverages are commonly produced from cereals and starchy roots but rarely from legumes and nuts, which are rich in protein and other nutrients. Thus, most local beverages in developing countries are low in nutrient and not nutritionally beneficial to consumers. Imported beverages on the other hand are expensive and calorie dense. They are mostly produced from synthetic colorants, flavorings and sweeteners, which could be toxic to the body. In this study, soy-walnut milk drinks were produced from various proportions (0:100; 10:90; 30:70; 50:50) of un-malted or malted soymilk and walnut milk blends. The proximate composition, mineral content, physicochemical properties and sensory attributes of the soywalnut drinks were evaluated. The range of the proximate composition of the soy-walnut milk drinks were 86.93-90.67%, 1.96-2.87%, 3.08-5.09% , 0.14-0.30%, and 2.18-6.89%, for moisture, proteins, fat, ash and carbohydrate, respectively. The mineral content of the soy-walnut milk drinks ranged from 0.97-2.38 ppm for iron, 22.13- 59.51 ppm for magnesium, 26.08-35.08 ppm for calcium, 2.71-3.25 ppm for sodium and 1.38-2.14 ppm for zinc. The physicochemical contents ranged from 4.95 -5.36%, 9.34-13.17%, 3.4-3.9% and 0.25 – 0.42%, for pH, total solid, total soluble solid, and total titratable acidity, respectively. Results of the sensory attributes indicated that soy-walnut drinks produced from 10% un-malted and 30% malted soymilk substitution were most preferred to consumers. Soy-walnut milk drinks could help in solving the problem of protein malnutrition and micronutrient deficiency problems in developing countries and increase the utilization of walnut in Africa.