Sweet lupin and whey protein concentrate as supplementants to utilize in semi–hard biscuit and its chemical properties

Abstract

This study aimed to supplement soft wheat flour with different levels of sweet lupin powder and/or whey protein concentrate for producing a semi hard sweet biscuit as a functional product and their effects on the chemical and physical properties of produced biscuit were carried out. The results indicate that lupin and whey protein had 3.94 and 7.5 times higher than those of wheat flour. Fat content was higher in lupin with 2 and 4 folds compared with wheat flour, respectively. Lupin had higher ash content with 1.3 and 8.30 folds than its corresponding value in whey protein and wheat flour. Regarding to fibers content, lupin represented 4.44 and 1.33 times higher than that of wheat flour and whey protein, respectively. Generally, the higher the supplementation level of lupin flour and whey protein, the higher the protein, lipid, fiber and ash contents, while the lower the carbohydrate one. The water activity (aw) values have been decreased with increasing supplementation levels of lupin flour and whey protein, which prove the ability of lupin flour and whey protein to capture water which limit the available water for reactions and will affect the shelf life of the products, The farinogram parameters showed an increase in development time by increasing the ratios of lupin and whey protein, The degree of softening increases in samples supplemented with lupin and whey protein. Gelatinization temperature was increased ranged between 58.5˚C in wheat flour to 66˚C in higher supplemented samples. While, the maximum gelatinization decreases by increase supplementation levels of lupin flour and whey protein. Hardness of biscuit increased by increasing supplementing wheat with levels of lupin powder and whey protein. The same trend was found in Fracturability which increased by increasing the supplementation. Resilience values ranged between 0.01 and 0.10, while adhesiveness values ranged between 0.01 and 0.80. Biscuit samples supplemented with 15% lupin powder and 7% whey protein had high score of color, crust appearance, texture, aroma, taste and overall acceptability. The lowest score of crust appearance, texture, aroma, taste and overall acceptability were in supplemented samples with 45% wheat flour, 40% lupin flour and 15% whey protein. The amino acids profile of biscuit sample supplemented with (15%) lupin flour and (7%) whey protein which demonstrates rising in all of amino acids compared to control one. Leucine came as a predominant essential amino acid (0.65%) in control sample raised with 1.75 fold to be 1.14% in supplemented one. Similar finding was also detected when total EAA was compared (raised with 1.8fold). Only cysteine and methionine were less than 0.5% in treated sample rather than those of control. Regarding to the NEAA, glutamic acid is the major NEAA in both of treated or untreated samples (3.3%). The total NEAA was raised by 1.37 fold owing to supplementation process with 15% lupin and 7% whey protein. Similar increasing fold was recorded when total EAA/ NEAA ratio was considered.