Production and chemical composition of alfalfa protein concentrate obtained by freezing

Freezing alfalfa leaf juice yielded a curd with a high protein content, consisting primarily of chloroplasts. A study was conducted to determine the influence of freezing method. Freezing in liquid nitrogen yielded only 90 g kg−1 less curd than did freezing in the chest freezer. Curd formation may be caused by destabilization of the colloidal structure of the chloroplasts by freezing. Chemical composition of frozen concentrate (FC) was investigated to characterize the concentrate chemically. The chemical composition (protein: 522 g kg−1, lipids: 134 g kg−1, soluble sugars: 21 g kg−1, starch: 48 g kg−1 and ash: 54 g kg−1) suggested that the FC was suitable for feeding to nonruminants.