Abstract

During cashew processing, many kernels are broken and cracked, which exposes them to rapid deterioration and thus negatively impacts their market value. Consequently, broken kernels represent non-exportable cashew by-products. In this study, milk was produced from broken cashew kernels as a value-added product and the effect of heat treatment time on the biochemical characteristics of this milk was determined in order to add value. The milk was boiled at 98°C for 45 min during which samples were regularly taken every 15 min and subjected to biochemical analysis. The water content of cashew milk decreased significantly (P<0.05) during this treatment, from 88.9% to 84.96%. Energy macronutrients were significantly concentrated during the 45 min treatment (p<0.001). Thus, carbohydrate, lipid and protein contents increased from 1.79% to 2.22%; 2.94% to 4.82% and 6.24% to 7.75%, respectively; and generate an energy value evolving from 58.58 to 83.26 Kcal. Also, boiling milk increases its mineral density and leads to the highest ash content (0.25%) after 45 min of treatment. This mineral concentration provided mineral salt contents from 171.7 to 285.8 mg Mg/L, 175.1 to 229.5 mg Fe/L, 100.6 to 101.4 mg Ca/L, 29.4 to 74.4 mg K/L, 46.4 to 60.9 mg Zn/L and 27.2 to 20.6 mg Na/L of product. In addition, heat treatment significantly influenced the presence of anti-nutritional factors (P<0.001) in cashew milk, leading to a decrease in the contents of tannins (19.52 mg/100 g DM), phytates (37.57 mg/100 g DM) and oxalates (44.52 mg/100 g DM) to values of 15.55, 28, 46 and 40.60 mg/100 g DM after 15 min, respectively, and then to their total absence after 30 min of treatment. Heat treatment increases the nutritional value of cashew kernel milk while removing the anti-nutrients typical of vegetable milks.