DEBITTERING OF LUPIN (LUPINUS-LUTEUS L) PROTEIN BY CALCIUM ALGINATE AND NUTRITIONAL-EVALUATION

A new process for debittering lupin (Lupinus luteus L) proteins by coa gulating in an aqueous medium was developed. The proteins of whole bit ter yellow lupin seed (BYL) were solubilized in an aqueous medium with alginic acid then coagulated in a bath of calcium chloride. This proc ess was also applied to sweet yellow lupin seeds and sweet white lupin , which are low alkaloid varieties. Crude protein content of the conce ntrates from the three varieties of lupin seeds and the yield at diffe rent pH levels were determined. The protein efficiency ratio of the lo w alkaloid protein concentrate (LAPC) from BYL was determined. The dai ly protein intake of LAPC diet was close to that of the untreated bitt er seed diet. However, the weight gain was lower (0.23 +/- 0.16 compar ed to 0.35 +/- 0.17 g day-1). Weight gains for both lupin diets were c onsiderably less than for rats fed a casein diet (4.74 +/- 0.49 g day- 1). Protein intake of LAPC supplemented with 2% (w/w) DL-methionine wa s comparable to that of casein (1.5 g day-1). However. the weight gain and the PER were significantly different: 3.66 +/- 0.62 g day-1 and 2 .02 +/- 0.20 g day-1, respectively, for rats on the low alkaloid prote in diet supplemented with methionine compared with 4.74 +/- 0.49 g day -1 and 2.50 +/- 0.15 g day-1 for rats on the casein diet.