POTENSI BAKTERI ASAM LAKTAT INDIGENOUS SEBAGAI PENGHASIL ANGIOTENSIN I CONVERTING ENZYME INHIBITOR PADA FERMENTASI BEKASAM

• Main Authors: , Prima Retno Wikandari, Dra.,M.Si., , Prof. Dr. Ir. Endang S. Rahayu, M.S.
• Format: Theses and Dissertations NonPeerReviewed
• Published: [Yogyakarta] : Universitas Gadjah Mada 2011
• Subjects: ETD
• Online Access: https://repository.ugm.ac.id/90525/; http://etd.ugm.ac.id/index.php?mod=penelitian_detail&sub=PenelitianDetail&act=view&typ=html&buku_id=53183
• Institution: Universitas Gadjah Mada

Bekasam is a traditional fermented product made from mixture of fish, rice, and salt in a certain composition. Since it is a fermented product of proteinaceus material by lactic bacteria, it was assumed that this product contains Angiotensin I Converting Enzyme (ACE) inhibitor from peptides activities as a result of protein degradation during bekasam fermentation. The enzyme changes Angiotensin I to Angiotensin II, which is responsible in triggering hypertension, hence inhibiting the enzyme prevents the occurence of hypertension. The research aimed (1) to identify the ACE inhibitor activities in bekasam prepared from selected fish types, (2) to identify the strain of indigenous proteolytic lactic acid bacteria of bekasam, (3) to identify selected proteolytic lactic acid bacteria capable of producing ACE Inhibitor, (4) to evaluate the potential of selected lactic acid starter in bekasam fermentation in order to enhanche the ACE inhibitor activity, (5) to analyse the fate of ACE inhibitor activity in bekasam extract under pepsin digestion in vitro, and (6) to analyze the stability of ACE inhibitor activity of bekasam after 45 day storage at 4 0 C. Result indicated that there are inhibition of ACE activity in bekasam prepared from tylapia (Oreochromis nilotikus L) representing of fresh water fish (56.41%), milk fish (Chanos chanos) representing of brackish water (66.07%), and tuna (Tunus sp.) representing sea water (70.74%). The total lactic acid bacteria, pH, and soluble protein in the three samples were relatively the same, which were 10 7 - 10 8 , 4.40 � 4.78, and 8.67 � 9.84 mg/g, respectively. Further identification on 150 lactic acid bacteria isolates indicated that the 6 of them showed characteristics of high proteolytic activity and homofermentative, which belong to the species of Lactobacillus plantarum B1765, L. plantarum B1465, L. plantarum N2352, L. plantarum T2565, L. pentosus B2555, and Pediococcus pentosaceus B1661. Fermentation of milk fish using the 6 isolates produced bekasam-like products with ACE Inhibitor activities, from the highest to the lowest, of 68.17% for L. plantarum B1765, 62.54% for L. plantarum T2565, 61.56% for L. plantarum N2352, 56.51% for the L.pentosus B2555, 56.47% for L. plantarum B1465, and 18.66% for P.pentocaseus B1666. The ACE inbitory activities showed correlation with the growth of the lactic acid bacteria population and the peptide concentration along the fermentation process of bekasam. It was assumed that the ACE Inhibitor activity were due to peptides as the result of the bacterial proteolytic acitivity. Upon intervention of spontaneous fermentation by addition of selected starter culture (L. plantarum B1765) showed about 10% increase in the activity of ACE inhibitor. The starter addition also increased the lactic acid bacteria population, peptide concentration, and reduced the fermentation time. Upon in vitro digestion using pepsin on both bekasam under spontaneous fermentation and that under spontaneous fermentation with starter culture addition did not show any marked changes in ACE inhibitor activities, which were 62.99% and 71.54% before digestion and 61.14% and 69.03% after digestion, respectively. It indicated that no further digestion on the residual proteins and/or peptides of the bekasam materials. The digestion stability need to be expanded with other gastro-intestinal enzymes to ensure that the peptide having ACE Inhibitor activity will stand during the digestion process. Storage of bekasams, made by spontaneous fermentation and that under spontaneous fermentation with starter culture addition, at 4oC for 45 days did not reduce the activities of ACE Inhibitor in both bekasam products.