Natural Cathepsin Inhibitor to Inhibit Milkfish Deterioration During Chilling Storage

Quality deterioration of fish is caused by various factors, one of them is due to the activity of cathepsin enzyme. Cathepsin enzyme activity can be inhibited by enzyme inhibitors. Inhibitors of the enzyme can be obtained from fish meat tissue by separating the enzyme-inhibitor complex with heat treatment. The purpose of this research was to extract and apply the cathepsin inhibitors to inhibit deterioration of fish quality. This research was conducted in three steps: (1) the determination of the optimum extraction temperature for extraction of cathepsin inhibitors, (2) the determination of the most potent cathepsin inhibitors with various concentrations, and (3) the application of cathepsin inhibitors in inhibiting the deterioration of fish quality. The results showed that the cathepsin inhibitors was optimally extracted at 80°C. Cathepsin inhibitors diluted using buffer with a ratio of 1: 1 had the same relative activity without dilution. The process of quality deterioration of milkfish control in chilling temperatures occured after 504 hours (21 days) storage with a 24-hour observation time interval. The complete process during observation was pre-rigor (0 hour ), rigor mortis (96 hours), post-rigor (360 hours), and deterioration (504 hours). The process of milkfish quality deterioration treated with soaking in cathepsin inhibitors occured after 624 hours (26 days) storage with the detailed process as follows: 0 hour (pre-rigor), 144 hours (rigor mortis), 408 hours (post-rigor), and 624 hours (deterioration). Thus fish marinated with cathepsin inhibitors achieve slower deterioration phase 5 days

Characterization of Functional Properties Fish Protein Concentrate of Skipjack Roe (Katsuwonus Pelamis)

By product that rich in protein such as fish roes are potential as raw material for protein concentrate. This research aimed to utilize skipjack roes to produce protein concentrate and to characterize its functional properties. The method used to extract protein was defatting method using isopropyl alcohol and ethanol with extraction times of 1, 2, and 3 hours. The results showed that skipjack roes contained 19.81% of protein, 3.41% of fat, 71.32% of moisture, 2.04% of ash, and 1.53% of carbohydrate (by difference). Defatting method using isopropyl alcohol for 3 hours produced the best roe protein concentrate (RPC). The product meets to the quality requirements of fish protein concentrate type B, contained protein and fat of 71.79% and 2.78%, respectively. This product also had functional properties as follows: water absorption capacity (1.57 ml/g), oil absorption capacity (1.82 g/g), emulsion capacity (81.65%), bulk density (0.51 g/ml), foaming capacity (1.90 ml), foaming stability (0.22 ml) and protein digestibility (95.86%). Lysine and leucine became the major essential amino acid of RPC, with values were 70.76 and 64.91 mg/g protein, respectively. The composition of amino acids of RPC skipjack consisted of 8 essentials amino acids, 5 non-essentials amino acids and 2 semi-essentials amino acids

Recovery of Flavor Components from Blue Crab Processing Wastewater By Reverse Osmosis Technology

The waste water of blue crab pasteurization is potential to cause environmental pollution. It contained TSS 206.5 mg/L, BOD 7,092.6 mg/L and COD 51,000 mg/L. However the was the water also contains an interesting flavor compounds, which composed of 0.23% non protein nitrogen and 17 amino acids with the highest being glutamic acid. In this work, pre-filtration steps using filter of 0.3 µ size followed by reverse osmosis has been used to reduce these pollutions load and recover the flavor compound. During pre-filtration steps, TSS was reduced to 74.8% so the turbidity increased up to 31%. After reverse osmosis process, BOD, and COD were decreased more than 99%, and there was no amino acids detected in the permeate stream. Factors that affect performance of reverse osmosis were transmembrane pressure, temperature and pH. Higher transmembrane pressure, temperature and pH resulted in the higher permeate flux. Key word : blue crab, flavor, reserve osmosi

Recovery of Flavor Components from Blue Crab Processing Wastewater By Reverse Osmosis Technology

The waste water of blue crab pasteurization is potential to cause environmental pollution. It contained TSS 206.5 mg/L, BOD 7,092.6 mg/L and COD 51,000 mg/L. However the was the water also contains an interesting flavor compounds, which composed of 0.23% non protein nitrogen and 17 amino acids with the highest being glutamic acid. In this work, pre-filtration steps using filter of 0.3 µ size followed by reverse osmosis has been used to reduce these pollutions load and recover the flavor compound. During pre-filtration steps, TSS was reduced to 74.8% so the turbidity increased up to 31%. After reverse osmosis process, BOD, and COD were decreased more than 99%, and there was no amino acids detected in the permeate stream. Factors that affect performance of reverse osmosis were transmembrane pressure, temperature and pH. Higher transmembrane pressure, temperature and pH resulted in the higher permeate flux. Key word : blue crab, flavor, reserve osmosi