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

Perceived sensory quality of unpolished pigmented and milled white rices

Purpose To explore and compare consumer perceptions of unpolished pigmented rice and milled white rice between unfamiliar and typical consumers. Design/methodology/approach This study first employed focus groups to explore attitudes and habits relating to rice consumption among British subjects. A sensory descriptive analysis method, Flash Profiling (FP), was then applied on consumer panels in the United Kingdom (UK) and Thailand to gain perceived sensory quality of unfamiliar and typical rice samples. The sensory profiles generated by British and Thai panellists were analysed by Generalised Procrustean Analysis (GPA) and compared based on perceived attributes, dominant characteristics and repeatability. Findings Focus group results suggested that consumer familiarity with rice might influence preferred rice textural quality. The prominent textures of stickiness and bittiness of unpolished pigmented rice were negatively associated with perceived quality in the UK participants The sensory profiles generated by GPA consisted of similarity with darkness of colour and sweet/ earthy type odours that are key dominant characteristics of the Thai pigmented rice. Practical implications The research has provided sensory information of the unpolished pigmented rice as compared with milled white rice. The information gives insights on product development directions for export and further research on rice processing and cooking instructions. Originality/value This study is the first to apply sensory evaluation in a cross-cultural comparison of pigmented rice

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

Water activity reduction of intermediate moisture yellowstrip trevally (Selaroides leptolepis)

Water activity reduction of intermediate moisture yellowstrip trevally was studied. The optimal time (8, 12, 16, 20 hrs.) for curing marinade was investigated. The effects of different humectants (glycerol, sorbitol, lactitol, glucose syrup) at 50% w/w of curing ingredients were compared. Results showed that moisture content and water activity of cured yellowstrip trevally decreased as curing time increased (p<0.05). The curing time did not affect shear force, L a b value or acceptability scores, as evaluated by nine-point hedonic scale (p>0.05). However, the hardness of intermediate moisture Yellowstrip trevally, determined by texture analyzer, decreased. Hardness, shear force, L a b value of sample added with various humectants were lower than those of the control (p<0.05), whereas shear force of lactitol-added samples were not different from that of the control (p>0.05). The glycerol-added samples had the highest overall acceptability score and were higher than control, whereas the glucose syrup-added samples had the lowest score. Moisture content of the samples with the addition of various humectants was higher than that of the control (18.28 %). The samples added with glycerol retained the highest moisture (24.94%). The adsorption isotherm studies showed that the equilibrium moisture of sample added with glycerol was higher than that added with lactitol

Formulation of Thai herbal Namprik

Namprik is a typical Thai food containing various herbs. The diversity of Namprik depends on herb composition and content, cooking method, and flavor. The objective of this study was to develop a fine, driedand granular Namprik formula for eating with rice. The ingredients included many commonly found Thai herbs. The recipe of lemon grass Namprik produced by Satree Ban-Tung group, Khaokram district, AmphurMueang, Krabi province, Thailand, was reformulated. Mixture design was applied to optimize the amounts of black pepper (10-33%), garlic (10-66.67%) and shallot (10-66.67%). Contour plot of hedonic scores andthe predictive regression models were calculated. Results showed that optimal formula should have 23.33% black pepper, 66.67% garlic and 10% shallot. Optimum levels of additional mixed herbs consisting of 5-25%kaffir lime leaves and 75-95% holy basil in the formula, using the mixture design, were also investigated. The results of sensory evaluation using 9-point hedonic scale showed no significant differences in appearance,taste and overall liking (p>0.05). However, the formula containing 4.2% kaffir lime leaves and 15.8% holy basil obtained the highest average score for aroma (p<0.05). Various amounts of dried African chili (7, 5,3%) were added to determine an acceptable hot and spicy flavor, using just-about-right scale. The results revealed that the formula containing 7, 5 and 3% dried African chili were defined as just-about-right by 22, 32 and 42% of the panelists, respectively. The final product was given average hedonic scores of aroma, taste,spicy and overall liking ranging from like moderately to like very much. Appearance scores were in the range of like slightly to like moderately. This study indicated that a more nutrition and healthier Namprik containing some Thai herbs can be produced

Replacement of cocoa butter with cocoa butter - like fat from modified palm oil in coating chocolate

Chocolate is a confectionery product, mainly containing cocoa mass or liquor, cocoa butter (CB) and sugar. Nowadays vegetable fats and modified oil are used instead of CB in chocolate products to lower the cost and to obtain the varieties of products with different characteristics and textures. Cocoa butter-like fat from modified palm oil (CBFMPO) at different levels of CB replacement (60,80 and 100%) were used to develop a formulation of coating chocolate. When physical and sensory properties were evaluated, the viscosity and coating ability on biscuit sticks were remarkedly decreased with increasing CBFMPO content. Hedonic mean scores of mouthfeel and coating ability of the chocolate containing 100% CBFMPO were greater than those of chocolate containing 60 and 80% CBFMPO (p<0.05). During storage of biscuit sticks dipped in the chocolate coating (chocolate containing 100% CBFMPO) at room temperature (27-29oC) and low temperature (20-22oC) for 30 days, blooming (as shown by whiteness index) occurred to a greater extent at higher temperature. At both storage temperatures, the intensity scores of glossiness and hedonic mean scores of overall liking of samples decreased but intensity scores of off-odor increased during the first 6 of days storage (p<0.05)

Effect of ice storage on muscle protein properties and qualities of emulsion fish sausage from bigeye snapper (Priacanthus tayenus) and lizardfish (Saurida undosquamis)

The chemical changes in fish muscle and natural actomyosin (NAM) from bigeye snapper (Priacanthus tayenus) and lizardfish (Saurida undosquamis) muscle during 0, 2, 4, 6, 8, 10, 12 and 14 days of iced storage were studied. Myosin heavy chain (MHC) of NAM extracted from two fish species was degraded throughout iced storage. However, no changes in actin were observed. The total volatile base (TVB). trimethylamine (TMA) and surface hydrophobicity increased, while the total sulfhydryl content and emulsion capacity of NAM from both fish species decreased significantly as the storage time increased (p<0.05). A Texture ProfileAnalysis (TPA) and shear force of emulsion fish sausages prepared from two fish species kept in ice for 0, 4, 8 and 12 days were investigated. The results showed that hardness, cohesiveness, gumminess, chewiness and shear force of sausage prepared from fish kept in ice were lower than those produced from fresh fish. However, no significant differences in adhesiveness were observed. Cooking loss of emulsion fish sausage from two fish species increased throughout storage time (p<0.05). The texture of bigeye snapper sausage was better than that of lizardfish sausages. Scanning electron microscopy (SEM) micrographs of emulsion fish sausage from two fish species revealed bigger voids, thicker strands and less continuity of protein strands with increasing storage time. More microstructural changes were observed in sausages from lizardfish, compared to those in sausages from bigeye snapper

A salt on the senses

Salt (NaCl) is essential for normal functioning in humans and the second most used food additive. However, high sodium (Na) consumption is a major contributor to high blood pressure. Globally, correlation exists between excessive sodium consumption and high blood pressure, which leads to possible coronary heart disease, stroke, heart and kidney failure. In the United States, the average daily Na intake is more than 3,400mg (equivalent to 8.5g salt), which exceeds the current maximum recommended intake level (2,300mg/d Na or 5.8g/d salt) established by the 2005 Dietary Guidelines for Americans. Individuals aged 51 years and older, and those of any age who are African American, or who have hypertension, diabetes, or chronic kidney disease should limit their Na intake to 1,500mg per day. In the US alone, more than 800,000 people die yearly from heart disease, stroke and other vascular diseases, costing a sum of $273 billion in healthcare dollars[1]. Awareness of potential negative effects of high Na consumption is critical for public safety