Trash fish is a fish with low selling value that needs an increased value by processing it into rusip (fermented fish) products. The research objective was to determine the effect of liquid palm sugar and salt concentrations on the physical, chemical, and microbiological properties of trash fish rusip. The research was arranged factorial in a completely randomized block design. The concentrations of liquid palm sugar were 5%, 10%, and 15% (v/w), while concentrations of salt were 20%, 25%, and 30% (w/w).  Using LSD at level 5% showed that the concentration of liquid palm sugar had a significant effect on total lactic acid bacteria and total lactic acid, while the salt concentration had a significant effect on pH and salt content. There was an interaction between two factors on the trash fish rusip water content, where the significant effect of liquid palm sugar concentration on water content was salt concentration-dependent.Keywords: chemical, microbiological, physical, rusip, trash fish.

Abstract. Rusip is a typical food of Bangka Belitung Indonesia made from fermented anchovy. This study aims to determine the properties of chemistry, microbiology, composition of amino acids and fatty acids from fermented fish spontaneously and non spontaneously. Spontaneous rusip treatment is done by anchovy fish (Stolephorussp) after cleaning and added salt 25% (w/w) and palm sugar 10% (w/w). While, non-spontaneous rusip is done by adding a culture mixture of Streptococcus, Leuconostoc, and Lactobacillus bacteria 2% (w/v). The materials are then incubated for 2 weeks. The data obtained were then performed t-test at the level of 5%. Spontaneous and non-spontaneous rusip fermentation process showed significant differences in total acid, reducing sugar, salt content, TVN, total lactic acid bacteria, total mold, and total microbial. The dominant amino acid content of spontaneous and non-spontaneous rusip are glutamic acid and aspartic acid, while the dominant fatty acids in spontaneous and nonspontaneous rusip are docosahexaenoic acid, palmitic acid, oleic acid, arachidonic acid, stearic acid, eicosapentaenoic acid, palmitoleic acid, and myristic acid.

This study aimed to find optimum manufacturing trash fish protein hydrolyzate using the commercial papain enzyme. It is known that fish protein hydrolysates have good functional properties, so it is more widely utilized, especially for food. The study was conducted in two stages, the first stage was to make trash fish protein hydrolyzate treated with enzyme concentration of 3%, 5%, 7% (w/w), and pH 5; 5.5; 6; 6.5; 7, whereas second stage was to make trash fish protein hydrolyzate with same from the first stage and so the best treatment followed by treatment of half-hour long incubation and one hour. Parameters observed were soluble protein, foamability, fat binding capacity and emulsion stability. The treatment was repeated three times and the first phase of data analysis using advanced testing LSD and the second stage using the T test. Results show that the best soluble protein to produce a trash fish protein hydrolyzate enzyme was at a concentration of 5% and pH = 6.5 that was equal to 19.71%. In half an hour incubation produce higher soluble protein values and foamability that were equal to 24.97% and 9.63%, while the binding capacity of fat in one hour incubation produces a higher value that was equal to 5.03%. Meanwhile, emulsion stability did not differ significantly at both incubation time.

This research aimed to (1) compare the characterization between rusip with Streptococcus sp. and without it, and (2) evaluate chemical, and microbiological. This research done in some steps which was (1) preparation of liquid starter, (2) making of dry starter, (3) application of Streptococcus sp. dry starter to rusip, the water content, level of acidity (pH), total lactic acid bacterial, total fungi, salt content and Nitrogen Volatile Total (NVT) are being monitory. The data were analysed by descriptively. Rusip that fermented for seven days with adding of Streptococcus sp.dry culture produced better pH, total of lactic acid bacterial, salt content, NVT content and also produce higher water content compare with spontaneously fermented rusip. However rusip fermented with adding of Streptococcus sp. dry starter still had weakness that was produce more fungi than spontaneouslyfermented rusip. Characteristic of rusip that fermented with adding of Streptococcus sp. dry starter were : content 57,87% of water, 5,77 pH, 3,98 x 1011 cfu/g of total lactic acid bacterial, 24,64% salt and 51,43 mgN/100g NVT

Abstract. Koesoemawardani D. Afifah LU, Herdiana N, Suharyo AS, Fadhallah EG, Ali M. 2021. Microbiological, physical, and chemical properties of joruk (fermented fish product) with different levels of salt concentration. Biodiversitas 22: 132-136. Joruk is a fermented fish product originated in Ogan Komering Ulu Timur, South Sumatra, Indonesia. The aim of this study was to determine the effect of salt on the microbiological, physical and chemical properties of joruk. This research was arranged in a Randomized Complete Block Design (RCBD), with treatment of salt concentrations at 5%, 10%, 15%, 20%, 25%, and 30% (w/w). The follow-up test used the Least Significance Difference (LSD) at 5%. The result of this study showed that the addition of 10% salt produced the best joruk with the best microbiological and chemical properties as follows: total LAB of 8.75 log cfu/g, total microbes of 13.25 log cfu/g, and total mold of 4.27 log cfu/g, pH of 5.85, total lactic acid of 2.97%, Total Volatile Base (TVB) of 153.05 mgN /100g, and water content of 59.33%. Based on this study, it is concluded that the addition of salt at different concentrations significantly affects the pH, total lactic acid, total lactic acid bacteria (LAB), and water content of joruk.