Effect of storage time of halal peptone at refrigerator temperature on bacterial growth

Abstract

Protein hydrolysate, such as peptone, is a protein molecule that contains amino acids and is one source of nitrogen used for microbial development. Commercial peptone is usually derived from animals; however, if it is not slaughtered according to Islamic law, it is not halal, except for pigs and dogs. Pangasius fillet waste (P) and pineapple core (C) are agro-industrial wastes with great potential as raw materials to produce halal peptone. This study aimed to evaluate halal peptone made from P and C with a ratio of 3:1 stored in cold temperatures as a medium for the growth of microorganisms. The research treatment was the storage of halal peptone for four storage periods, namely T1 = 0 wk, T2 = 1 wk, T3 = 3 wk, and T4 = 4 wk at 4°C. At each storage time, peptone was inoculated with L. plantarum strain TMW 1.1623, S. thermophilus, Escherichia coli, and Listeria monocytogenes. Total L. plantarum strain TMW 1.1623 and S. thermophilus at 0 wk were 10.14 and 11.17 log CFU/mL, respectively, which were significantly different (P<0.05) with total LAB in other treatments for each LAB strain. On the other hand, the growth of pathogenic bacteria was not affected (P>0.05) by the storage time of halal peptone at 4°C. This study concludes that the halal peptone solution stored at 4°C can still be used as a growth medium for LAB or pathogenic bacteria.

Physicochemical, Microbiological, and Sensory Characteristics of Yoghurt Produced by Back-Sloping Fermentation

“…: S00202107566) contains peptone hydrolyzed from Pangasius fillet waste to propagate LAB. Two LAB strains, namely L. plantarum TMW 1.1623 and S. thermophilus, were grown at -20°C in the laboratory on this medium (Rossi et al, 2022). To obtain active cultures for making yogurt starters, the inoculated pure cultures were then incubated for 24 hours at 37°C.…”

“…The pH of the yoghurt in all batches, including the control, was assessed using a portable pH meter equipped with a glass electrode after 8 hours of fermentation (Rossi et al, 2022).…”