KERNEL EXTRACTION AND MACHINE EFFICIENCY IN DEHULLING PARBOILED AFRICAN BREADFRUIT (TRECULIA AFRICANA DECNE) WHOLE SEEDS

Abstract

ABSTRACT Parboiling and dehulling are two closely associated primary operations preceding African breadfruit (Treculia africana) seed kernel extraction and subsequent utilization in any food form. Three process variable conditions for parboiling the seeds (quantity of parboiled seeds, parboiling temperature and parboiling time) for dehulling and kernel extraction were investigated using a central composite design. The objectives of the research were to maximize kernel and extraction yields and dehulling and machine efficiencies through process variable combinations. Maximum kernel mass (91.33%) was obtained at the center point process combination (12 kg, 80C and 13 min, respectively). Extraction yield and total recovered wastes were 94.08 and 7.31%, while dehulling and machine efficiencies were 72.62 and 96.97%, respectively. Models developed by response surface analysis for these responses ranged from 62 to 93%. Temperature effects on kernel mass, extraction yield and total wastes were both linear and quadratic.PRACTICAL APPLICATIONSDehulling operation, to a great extent, is dependent on parboiling process conditions. This research located the optimum combination of process variables that would lead to maximum kernel yield and machine efficiency using second‐order central composite design and response surface analysis. It also reported the ability of locally fabricated power‐driven commercial attrition mill, designed for grinding cereals and grain‐legumes, to thresh and dehull parboiled African breadfruit whole seeds. Because the seeds are extracted,parboiled and dehulled before their utilization in any food form, information obtained in this research would be needful not only to processors of African breadfruit seeds, but also to those processing grain‐legumes and other seeds requiring dehulling process before conversion into any food form.