Oysters and mussels are known vectors of foodborne pathogens because of their immobile and filter-feeding nature leading to the accumulation of biological particles in their tissues. Accumulated bacteria which comes from the culture environment and unsanitary handling can cause food poisoning if these shellfish are consumed raw or partially processed. This study determined the incidence of bacterial pathogen contamination along the different channels of the oyster and mussel supply chain through a time-distribution simulation analysis. First, the route of the fresh bivalve products from a local farm to its market was established through interviews. From the data gathered, a simulation experiment was conducted following the observed time-temperature conditions and the actual bulk packaging material used by the traders. The presence of target pathogens Escherichia coli, Salmonella spp., Vibrio parahaemolyticus, and Vibrio cholerae were detected using standard conventional culture techniques. Initial E. coli counts in both mussels and oysters were higher than the safety limit of 330 MPN in 100 g tissue. Interestingly, E. coli counts in mussels decreased after 6 h and maintained low numbers after more than 24 h postharvest. Counts in oysters however increased to 1000 MPN in 100 g tissue. V. parahaemolyticus in mussels and oysters showed a gradual increase in counts with increasing holding time albeit in numbers that are lower than the safety limit of 1000 cfu g^-1 tissue. Qualitative detection of Salmonella and V. cholerae showed the presence of both pathogens in all the sampling points. All four pathogens were also detected in the culture waters and in the sediment. Results of the study showed that the culture environment and the handling practices contribute greatly to the pathogen contamination in oysters and mussels.

Tuna is abundant in the Philippines, but the by-products during processing in various forms may be a source of waste and environmental pollution. To minimize these wastes, they are utilized directly or fermented to serve as food for humans and animals and as a functional food ingredient since they are rich in proteins and polyunsaturated lipids. For this purpose, they are often converted into protein hydrolysates using proteolytic enzymes. This study optimized the hydrolysis of the yellowfin tuna (Thunnus albacares) viscera (YFTV) using the enzyme neutrase to produce hydrolysates with a high degree of hydrolysis (DH) and foaming capacity (FC). Using the central composite design of the Response Surface Methodology (RSM), the YFTV protein hydrolysis at varying concentrations (0.5-1.5%, w/v) and hydrolysis time (60 to 180 min) was carried out. From the RSM-generated model, the optimum conditions to obtain the highest DH was 179.50 min hydrolysis time and 1.5% enzyme concentration, and for the highest FC, 176.58 hydrolysis time and 1.5% enzyme concentration. The predicted optimum values using the generated linear and quadratic equations were 17.26% DH and 1.60% FC. The lack of a fit test for both responses yielded an insignificant value (p > 0.05) for the model, suggesting that the regression coefficient was sufficient for estimating both responses under any group of variables. The optimized protein hydrolysis conditions of YFTV using Neutrase could be applied in food production systems, especially downstream processing. Furthermore, the utilization of tuna viscera as protein hydrolysates could potentially contribute to the waste management of these processing by-products.

Seaweeds are increasingly valued in the food industry for their bioactive compounds, mainly hydrocolloids like carrageenan. This study investigates E. perplexum, a red seaweed, as a unique and sustainable source of carrageenan with promising functional properties. Using response surface methodology (RSM), the extraction process was optimized through alkaline extraction, identifying optimal conditions of 85 °C for 3 h with 2.58 M KOH, which yielded 77.10% carrageenan. The extracted carrageenan exhibited strong emulsifying activity (71.53 ± 2.41) and color properties comparable to commercial carrageenan, highlighting its viability for food applications. Chemical evaluation revealed a higher sulfate content (8.45 ± 0.16) and slightly reduced carbohydrate levels, which may influence its gelling and stabilizing abilities. Structural examination through ATR-FTIR spectroscopy corroborates the presence of key functional groups, including sulfate esters and galactose derivatives, inferring molecular integrity. These results emphasize the importance of RSM in optimizing extraction and underscore the ability of E. perplexum as a promising source of the derived carrageenan, which is a high-performance additive in food systems. Further research on purification, functional enhancement, and safety assessment is recommended to facilitate its integration into commercial food systems.

Introduction/Objective:: Fish are a rich source of lipids, particularly omega-3 polyunsaturated fatty acids (PUFAs), which are known to reduce cardiovascular disease risk and support human health. Processing of fish generates significant by-products, including heads, viscera, and tails, which contain recoverable lipids. Conventional extraction methods often involve high temperatures and toxic solvents, compromising lipid bioactivity and safety. This study aimed to optimize enzymatic hydrolysis using Alcalase® for lipid recovery from sardine (Sardinella spp.) processing wastes and to evaluate the quality and biological activities of the refined oil. Methods:: Oil extraction was optimized using a central composite design of response surface methodology (RSM) with three independent variables: hydrolysis time, enzyme concentration, and temperature. Recovered oil was refined through degumming, neutralization, bleaching, and deodorization. The refined oil was analyzed for physicochemical quality parameters, fatty acid profile, and bioactivities, including antioxidant and anti-inflammatory effects. Results:: Optimal hydrolysis conditions were 3 h, 0.80% enzyme concentration, and 57.5°C, yielding 8.74% ± 0.12 crude oil. Refining improved key quality indices, including peroxide value, thiobarbituric acid reactive substances, free fatty acids, fatty acid composition, and color, while retaining PUFA content. EPA and DHA concentrations increased to approximately 52–59%. Refined oil exhibited notable bioactivities such as DPPH scavenging activity (23.47– 55.97%), cyclooxygenase-2 inhibition (26.38–81.94%), 5-lipoxygenase inhibition (22.51– 70.41%), and protein denaturation inhibition (34.9–89.6%). Discussions:: Results of the study revealed that using RSM in optimizing enzymatic conditions resulted in maximum oil recovery. Oil yield was affected by the interactive effects of the hydrolysis time and temperature, and enzyme concentration. Increasing the extraction time and enzyme concentration enhanced oil yield up to the optimum point. Refining the extracted oil removed impurities and oxidation products without reducing PUFA levels, thereby increasing biological activities. Conclusions:: Enzymatic hydrolysis and subsequent refining of sardine processing waste efficiently recover bioactive lipids with retained PUFA content. The refined oil demonstrates significant antioxidant and anti-inflammatory activities, highlighting its potential as a natural alternative to synthetic drugs and as a sustainable source of functional ingredients for nutraceutical and functional food applications.