Judul: Reduksi Aflatoxin M1 dalam Susu oleh Mikroorganisme yang Diisolasi dari Biji Kefir
Abstrak: One of the nutritious source that widely consumed including children and elderly is milk. However milk is not always free of contamination that can endanger people who consumed it, especially to children and elderly who are more prone to contamination. One of the most toxic mycotoxin is aflatoxin B1 (AFB1) which is mainly produced by Aspergillus flavus and Aspergillus parasticus. Those molds can grow on feed that is fed to the cow and converted inside the cow to aflatoxin M1 (AFM1). AFM1 considered as potential hazard because it almost has the same structure as AFB1 although only has 10% of AFB1 toxicity. AFM1 also is highly resistant to heat so it can survive on milk heating process. Mycotoxin can be reduced by several methods, such as chemical, physical and biological methods. Biological method with microorganism antagonism is one of the emerging methods because unlike chemical methods, microbial method use microorganism that belongs to GRAS (Generally Recognize as Safe). Decontamination method with microorganism usually done with lactic acid bacteria (LAB) or yeast. LAB and yeast can reduce AFM1 that contaminate milk. LAB and yeast can be found in kefir. Kefir is a fermented milk product which is made from cow or goat milk with kefir grains as starter. Kefir is known for its beneficial effect for health because of the metabolites that microorganism in kefir grains produce, such as lactic acid, kefiran, and bacteriocin. Kefir has complex bacterial composition that is varies according to the medium, origin of kefir grains, and storage condition. Hence microorganism from kefir grains has potential to reduce AFM1 in milk. This research was conducted to to compare the reduction ability of microorganism isolated from kefir grains with different incubation time and identify the strain of lactic acid bacteria and yeast that can effectively reduce AFM1 In general, this research was conducted through this following stages : (1) Preparation ; (2) Enumeration and isolation of microorganism from kefir grains (3) Column Preparation (4) Evaluation of reduction of AFM1 by microorganism isolated from kefir grains (5) Identification of LAB and yeast strains from kefir grains that can reduce AFM1. The result of the research showed that there were more aerobic lactic acid bacteria than anaerobic lactic acid bacteria in kefir grains. The means of colony count of anaerobic lactic acid bacteria, aerobic lactic acid bacteria, total yeast of kefir grains were 1.9 x 109 CFU/g, 2.1 x 109 CFU/g, 2.0 x 108 CFU/g respectively and in kefir milk were 1.0 x 108 CFU/g, 1.0 x 108 CFU/g, 7.6 x 107 CFU/g respectively. Evaluation of AFM1 reduction was done by microorganism isolated from kefir grains, namely anaerobic lactic acid bacteria (LAN), aerobic lactic acid bacteria (LAE) and yeast (YEA). This experient successfully isolated 10 isolates of LAE, 4 isolates of LAN and 9 isolates of YEA. This study used non-viable cell, for approximately 1.0 x 108 cfu/mL of microorganism to reduce 10 ng/mL AFM1 in Phosphate Buffer Saline (PBS). Non-viable cell was used for this experiment because past studies observed that non-viable cells showed higher percentages of AFM1 removal in a
Keyword: AFM1, decontamination, kefir grains, lactic acid bacteria, yeast