Physical and functional properties of fish gelatin-based film incorporated with mangrove extracts.

Background: The fishery processing industry produces a remarkable number of by-products daily. Fish skin accounts for one of the significant wastes produced. Fish skin, however, can be subjected to extraction to yield gelatine and used as the primary raw material for edible film production. To increase the functionality of edible films, bioactive compounds can be incorporated into packaging. Mangroves produce potential bioactive compounds that are suitable as additional agents for active packaging. This study aimed to create a fish gelatine-based edible film enriched with mangrove extracts and to observe its mechanical and biological properties. Methods: Two mangrove species (Bruguiera gymnorhiza and Sonneratia alba) with four extract concentrations (control, 0.05%, 0.15%, 0.25%, and 0.35%) were used to enrich edible films. The elongation, water vapour transmission, thickness, tensile strength, moisture content, antioxidant and antibacterial properties of the resulting packaging were analysed. Results: The results showed that the mangrove species and extract concentration significantly affected (p < 0.05) the physical properties of the treated films such as elongation (16.89-19.38%), water vapour transmission (13.31-13.59 g/m2), and active packaging-antioxidant activities (12.36%-60.98%). The thickness, tensile strength, and water content were not significantly affected. Potent antioxidant activity and relatively weak antimicrobial activity of this active gelatine packaging were observed.

Physicochemical and sensory properties of terasi (an Indonesian fermented shrimp paste) produced using Lactobacillus plantarum and Bacillus amyloliquefaciens.

Terasi is an Indonesian shrimp paste that is traditionally fermented and is widely consumed by Indonesian people. Terasi is produced by utilizing endogenous bacteria from raw materials as starters. Due to the variation in endogenous bacteria during production, terasi of varying quality is produced. The objectives of this study were to investigate the effects of starters on the physicochemical and sensory properties of terasi. The effects of individual or combination inoculation of Lactobacillus plantarum SB7 and Bacillus amyloliquefaciens BC9 were compared to those of noninoculation during a two-week period of terasi production. The starters darkened the color of the terasi. The terasi produced with the starters had higher protein contents (62.93-64.80 %) than those of the noninoculated terasi (63.66-65.80 %). Although proteolysis was weakly affected by the starters, the starters reduced the terasi fermentation period. The combination starter inoculation resulted in a high glutamic acid level (44284.8 ± 231.22 mg/kg). Volatile alcohols were more abundant in the starter-inoculated terasi than in the noninoculated terasi. Assessments of the sensory parameters by panelists suggested a preference for inoculated terasi. In conclusion, the addition of starters (L. plantarum SB7 and B. amyloliquefaciens BC9) in terasi production improved the physicochemical and sensory properties of the terasi.

Production and characteristics of fish protein hydrolysate from parrotfish (Chlorurus sordidus) head.

BACKGROUND: Fish byproducts are commonly recognized as low-value resources. In order to increase the value, fish byproducts need to be converted into new products with high functionality such as fish protein hydrolysate (FPH). In this study, FPH manufactured from parrotfish (Chlorurus sordidus) heads using different pH, time and sample ratio was investigated. METHODS: Hydrolysis reactions were conducted under different pHs (5, 7, and 9) and over different durations (12 and 24 h). Control treatment (without pH adjustment (pH 6.4)) and 0 h hydrolsisis duration were applied. Hydrolysates were characterized with respect to proximate composition, amino acid profile, and molecular weight distribution. The antioxidant activity of the hydrolysate was also observed. RESULTS: The pH and duration of hydrolysis significantly affected (p < 0.05) the characteristics of FPH. The highest yield of hydrolysate (49.04 ± 0.90%), with a degree of hydrolysis of 30.65 ± 1.82%, was obtained at pH 9 after 24 h incubation. In addition, the FPH had high antioxidant activity (58.20 ± 0.55%), with a high level of essential amino acids. Results suggested that FPH produced using endogenous enzymes represents a promising additive for food and industrial applications.

Relationship between levels of the heavy metals lead, cadmium and mercury, and metallothionein in the gills and stomach of Crassostrea iredalei and Crassostrea glomerata.

Background: The objective of this study was to compare the levels of heavy metals (Pb, Hg, and Cd) and metallothionein (MT) in the gills and stomach of two species of mussels ( Crassostrea iredalei and Crassostrea glomerata), and to observe the ability of the mussels to absorb the heavy metals Pb, Hg and Cd present in the water. Methods: The mussels were obtained from Mayangan, Kenjeran and Gresik ports, East Java, Indonesia. MT levels were determined using ELISA. Heavy metal levels of Pb, Hg and Cd were assayed using atomic absorption spectrophotometry. Results: The levels of Pb and Cd in water were below the maximum permissible levels for local water quality standards. By contrast, the level of Hg in the water was above the maximum permissible levels for water quality standards. At Mayangan Port (Station 1), the level of Pb was higher than Hg and Cd. Levels of MT and heavy metals varied greatly among of C. iredalei and C. glomerata individuals, but were always higher in the gills than in the stomach. The highest MT level (160,250 ng/g) was observed at Kenjeran Port (Station 2). MT levels were shown to be significantly associated with heavy metal level ( P<0.0001). Conclusions: This result indicates that MT may be responsible for the sequestration of these heavy metals, as has already been observed in terrestrial animals.

Antioxidant and cytotoxic activity of Acanthus ilicifolius flower.

OBJECTIVE: To investigate the antioxidant and cytotoxic activity of the flower of Acanthus ilicifolius (A. ilicifolius). METHODS: Antioxidant activity was determined as antiradical efficiency with diphenyl picrylhydrazil (DPPH) method and cytotoxic assay was undertaken using brine shrimp lethal toxicity test. RESULTS: A. ilicifolius flower contained terpenoid, phenolic compounds, and alkaloid. The methanol extract of A. ilicifolius flower showed the highest antiradical efficiency (AE=1.41×10(-3)) against DPPH radicals and the highest cytotoxicity (LC50=22 µg/mL) against brine shrimp nauplii. CONCLUSIONS: It is suggested that active compounds of A. ilicifolius flower solved in methanol play a role to inhibit free radical activity and kill Artemia salina nauplii. The substances can be considered as potential antioxidant and cytotoxic agents as well as imminent candidate for cancer therapy.

Antioxidant and cytotoxic activity of Acanthus ilicifolius flower

Objective: To investigate the antioxidant and cytotoxic activity of the flower of Acanthus ilicifolius (A. ilicifolius). Methods: Antioxidant activity was determined as antiradical efficiency with diphenyl picrylhydrazil (DPPH) method and cytotoxic assay was undertaken using brine shrimp lethal toxicity test. Results: A. ilicifolius flower contained terpenoid, phenolic compounds, and alkaloid. The methanol extract of A. ilicifolius flower showed the highest antiradical efficiency (AE=1.41í10-3) against DPPH radicals and the highest cytotoxicity (LC50=22 μg/mL) against brine shrimp nauplii. Conclusions: It is suggested that active compounds of A. ilicifolius flower solved in methanol play a role to inhibit free radical activity and kill Artemia salina nauplii. The substances can be considered as potential antioxidant and cytotoxic agents as well as imminent candidate for cancer therapy.