Leaf protein concentrate of Indigofera zollingeriana as a source of protein and branched-chain amino acids for ruminants

Abstract

Abstract Indigofera zollingeriana (I zollingeriana) leaves contain high-level protein and amino acids. Thus, it can be used as a leaf protein concentrate (LPC) source. This study aimed to obtain LPC from I. zollingeriana as feed supplement for ruminants. LPC was prepared by extracting I. zollingeriana leaves using distilled water and 0.1 N NaOH with a ratio of 1:3. The extraction was done by adjusting the pH of the liquid extract at pH 2, 3, 3.5, 4, 4.5, 5, 5.5, 6, by adding 0.1N HCl. Each pH determination was repeated three times. The pH and precipitate values were regressed to determine the isoelectric pH, which indicated the highest amount of LPC obtained from the extraction. LPC was produced based on its isoelectric pH, and its composition was analyzed. The results showed that the isoelectric pH of I. zollingeriana leaf extraction using distilled water was higher at pH 4.9 compared to 0.1N NaOH extraction, which had a pH of 4.3. Additionally, the total precipitate obtained from the distilled water extraction (0.2044 g/ml) was greater than that obtained from the NaOH extraction (0.1870 g/ml). I. zollingeriana LPC extracted with distilled water produced LPC’s yield of about 3.64% of fresh I. zollingeriana leaf and produced 53.58% of CP. I. zollingeriana LPC had complete amino acids with an increase in the branched-chain amino acids (BCAAs) valine, leucine, and isoleucine by an average of 91.5%. It can be concluded that Indigofera zollingeriana LPC contains higher protein content and BCAAs.