276 research outputs found
Development of Gelatine-based Bio-film from Chicken Feet Incorporated with Sugarcane Bagasse
Purpose
Protein-based films have good barrier characteristics against gas compared to synthetic films, but they have poor mechanical properties and high water vapour permeability (WVP) due to their hydrophilic nature. Sugarcane bagasse (SCB) is available abundantly in Southeast Asian countries and can be potentially utilized for its cellulose to increase the stiffness of the film. Hence, the purpose of this study was to develop a gelatine-based film from chicken feet incorporated with SCB.
Design/methodology/approach
Film-forming solutions (FFS) from chicken feet gelatine with different percentages of glycerol (25 and 35 per cent) were prepared by casting 4.0 g of FFS onto a rimmed silicone resin plate (50 × 50 mm2). Cellulose from SCB was purified and used to prepare hydrolyzed SCB. Films with 35 per cent glycerol were selected to be incorporated with different weight percentages (2.5, 5.0, 7.5 and 10.0 per cent) of hydrolyzed SCB to increase the tensile strength (TS) and lower the WVP of the films. Mechanical properties, colour and transparency of the films were also tested.
Findings
Films containing 35 per cent glycerol have lower TS but higher elongation at break compared to films prepared with 25 per cent glycerol. There were no significant differences between the films with 25 per cent and 35 per cent glycerol in thickness, WVP and transparency value tests. Film incorporated with 5.0 Wt.% SCB had a slight increment in TS (23.07 MPa) compared to the control film (22.50 MPa). WVP was also lowered from 2.18 × 10−11gm−1s−1Pa−1 to 1.85 × 10−11gm−1s−1Pa−1. The other properties, namely, thickness, colour measurement and transparency value, were significantly different (p < 0.05) but nearer to the properties of the control film.
Originality/value
This study incorporates hydrolyzed SCB to study the potential mechanical benefits in protein-based bio-films. There is potential to utilize agricultural waste (chicken feet and SCB) to develop food packaging films.
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Effect of antioxidants and packing conditions on storage stability of cereal bar fortified with hydrolyzed collagen from seabass skin
Effect of antioxidants (green tea powder (GT) and citric acid (CA)) and packing conditions on storage stability of cereal bar fortified with hydrolyzed collagen (HC) from seabass skin was studied up to 6 months of storage at 25°C in dark. Up to 3 months of storage, the addition of antioxidants impeded lipid oxidation, especially those cereal bars packed in polypropylene with normal heat seal (PP). Changes in moisture content, water activity, color, texture, PV, TBARS and formation of volatiles were effectively retarded when samples were packed under N 2 gas in laminated polyethylene/aluminium foil bag (LF) for 6 months of storage
Effect of Listeria monocytogenes inoculation, sodium acetate and nisin on microbiological and chemical quality of grass carp Ctenopharyngodon idella during refrigeration storage
In this study, the microbiological quality and lipid oxidation of the grass carp (Ctenopharyngodon idella) fillets treated by dipping in sodium acetate (0, 1 and 3%), nisin (0, 0.1 and 0.2%) or their combination were evaluated during 16 days of refrigeration storage. Antilisterial effect of nisin was enhanced with the increased concentration of sodium acetate. With increasing the concentrations of sodium acetate, mesophilic counts were lower but regarding nisin, better results were obtained by applying 0.1% nisin. Greater inhibition of mesophile bacteria was observed when combination treatment was used. The number of lactobacillus was lower when higher concentrations of sodium acetate and nisin were used. Peroxide, TBA and total viable base nitrogen (TVB-N) values were lower in the samples treated with both nisin and sodium acetate and higher results were obtained in the combination treatments.Key words: Listeria monocytogenes, nisin, sodium acetate, microbial quality, chemical quality, grass carp
Differences in textural properties of cooked caponized and broiler chicken breast meat
This study was aimed at evaluating textural properties of cooked chicken breast meats obtained from 3 production systems (conventional raising, feed modification, and caponization) and determining the relationship between instrumental parameters and sensory attributes associated with the texture of capon meat. Texture of cooked breast meats was determined using 3 instrumental methods: Warner-Bratzler Shear (WBS), texture profile analysis (TPA), and uniaxial compression (UC), and sensory analysis by trained panelists. The results indicated that cooked caponized meat showed the lowest values of WBS force, shear energy, hardness, Young's modulus of UC, and the 2 sensory attributes (firmness and number of chews) (P < 0.05). In contrast, springiness and juiciness were the highest in the caponized meat (P < 0.05), suggesting that capon meat was more tender and juicier than the others. Feed-modified chicken samples showed intermediate textural characteristics between the samples of capon and conventionally raised broiler. Pearson's correlation revealed that WBS force, shear energy, Young's modulus of UC, gumminess, and springiness were strongly correlated with 3 sensory attributes (firmness, number of chews, and juiciness). Partial least squares regression (PLSR) demonstrated that 72% of all sensory attributes for the first 2 PLSR components were explained by 36% of the instrumental parameters and the production systems. Loading and score plot illustrated that conventional raising contributed to a high degree of firmness and number of chews, and positively correlated with shear energy, WBS force, gumminess, hardness, and Young's modulus. Contrarily, caponization was negatively correlated with those sensory attributes. The univariate analysis indicated that firmness and number of chews were positively correlated with all instrumental parameters, except springiness. Juiciness was positively correlated with springiness but negatively correlated with the others. The study suggested that the cooked meat of capons could be differentiated from those of broilers raised conventionally and with feed-modified diets based on textural properties. Based on the optimized simulating equation, texture of caponized breast could be explained by WBS force, shear energy, Young's modulus, and gumminess
Effect of Protein Additives on Gelling Properties of Pacific White Shrimp (Litopenaeus vannamei) Meat 65
Abstract: In this study, the effects of egg white (EW), whey protein concentrate (WPC) and bovine plasma protein (BPP) at various concentrations (0 -3%) on properties of Pacific white shrimp gels were elucidated. For one-step heating (90 o C/20 min) and two-step heating (40 o C/30 min followed by 90 o C/20 min), all protein additives showed inhibitory activity toward autolysis of Pacific white shrimp gels. The inhibition was more pronounced in one-step heated gel when the level of protein additive increased which was reflected in the greater extent of myosin heavy chain (MHC) retained. The addition of 0.5% BPP exhibited the most gel enhancing effect as indicated by the highest increase in breaking force of 211.9% and 283.3% for one-step and twostep heated gels, respectively. The addition of BPP resulted in a decrease in L*-value of two-step heated gel and an increase in b*-value. Conversely, EW increased the L*-value, particularly at higher levels of addition
Measuring and decomposing inequity in self-reported morbidity and self-assessed health in Thailand
<p>Abstract</p> <p>Background</p> <p>In recent years, interest in the study of inequalities in health has not stopped at quantifying their magnitude; explaining the sources of inequalities has also become of great importance. This paper measures socioeconomic inequalities in self-reported morbidity and self-assessed health in Thailand, and the contributions of different population subgroups to those inequalities.</p> <p>Methods</p> <p>The Health and Welfare Survey 2003 conducted by the Thai National Statistical Office with 37,202 adult respondents is used for the analysis. The health outcomes of interest derive from three self-reported morbidity and two self-assessed health questions. Socioeconomic status is measured by adult-equivalent monthly income per household member. The concentration index (CI) of ill health is used as a measure of socioeconomic health inequalities, and is subsequently decomposed into contributing factors.</p> <p>Results</p> <p>The CIs reveal inequality gradients disadvantageous to the poor for both self-reported morbidity and self-assessed health in Thailand. The magnitudes of these inequalities were higher for the self-assessed health outcomes than for the self-reported morbidity outcomes. Age and sex played significant roles in accounting for the inequality in reported chronic illness (33.7 percent of the total inequality observed), hospital admission (27.8 percent), and self-assessed deterioration of health compared to a year ago (31.9 percent). The effect of being female and aged 60 years or older was by far the strongest demographic determinant of inequality across all five types of health outcome. Having a low socioeconomic status as measured by income quintile, education and work status were the main contributors disadvantaging the poor in self-rated health compared to a year ago (47.1 percent) and self-assessed health compared to peers (47.4 percent). Residence in the rural Northeast and rural North were the main regional contributors to inequality in self-reported recent and chronic illness, while residence in the rural Northeast was the major contributor to the tendency of the poor to report lower levels of self-assessed health compared to peers.</p> <p>Conclusion</p> <p>The findings confirm that substantial socioeconomic inequalities in health as measured by self-reported morbidity and self-assessed health exist in Thailand. Decomposition analysis shows that inequalities in health status are associated with particular demographic, socioeconomic and geographic population subgroups. Vulnerable subgroups which are prone to both ill health and relative poverty warrant targeted policy attention.</p
Evaluation of Physicochemical and Antioxidant Properties of Peanut Protein Hydrolysate
Peanut protein and its hydrolysate were compared with a view to their use as food additives. The effects of pH, temperature and protein concentration on some of their key physicochemical properties were investigated. Compared with peanut protein, peanut peptides exhibited a significantly higher solubility and significantly lower turbidity at pH values 2–12 and temperature between 30 and 80°C. Peanut peptide showed better emulsifying capacity, foam capacity and foam stability, but had lower water holding and fat adsorption capacities over a wide range of protein concentrations (2–5 g/100 ml) than peanut protein isolate. In addition, peanut peptide exhibited in vitro antioxidant properties measured in terms of reducing power, scavenging of hydroxyl radical, and scavenging of DPPH radical. These results suggest that peanut peptide appeared to have better functional and antioxidant properties and hence has a good potential as a food additive
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