Saowakon Wattanachant

Effect of crosslinking reagents and hydroxypropylation levels on dual-modified sago starch properties

Chemical modification is usually carried out to overcome the unstable properties of native sago starch and improve its physical properties during processing. In this study, dual-modification of sago starch was carried out. The first stage of modification was hydroxypropylation, using propylene oxide at levels ranging from 6 to 12%. This was followed by crosslinking, using three different types of crosslinking agents: a mixture of sodium trimetaphosphate (STMP) and sodium tripolyphosphate (STPP), phosphorus oxychloride and epichlorohydrin. Through hydroxypropylation, it was found that there was a significant increase in molar substitution which in turn induces an increase in crosslinking and this was seen from the marked increase in phosphorus content and degree of substitution. This was accompanied by a significant decrease in paste clarity, swelling power and solubility compared to that of the native starch. Starch that was hydroxypropylated with 10–12% propylene oxide and crosslinked by a mixture of 2% STMP and 5% STPP produced modified starch with the most desirable properties in that it exhibited no viscosity breakdown, high acid resistance, high freeze-thaw stability and improved gel texture.

Effect of phosphate treatments on microbiological, physicochemical changes of spent hen muscle marinated with Tom Yum paste during chilled storage

BACKGROUND This research aimed to study the effect of phosphate on quality of ready-to-cook spent hen muscle marinated with Tom Yum paste, a famous Thai food made from chilli, lime leaves and garcinia (pH 2.5-2.9). The effects of phosphate treatments (phosphate types, soaking time, and phosphate concentration) on physical characteristics of spent hen muscle in high acid condition were investigated. Quality changes of muscles pretreated with or without phosphate and marinated with Tom Yum paste were determined during storage at 4 degrees C for 30 days. RESULTS The acidified muscle pretreated with 40 g L(-1) sodium tripolyphosphate for 10 h had the highest marinade absorption, and the lowest cooking loss and shear force among all treatment samples. Microstructures of acidified muscle pretreated with and without sodium tripolyphosphate showed significant swelling with larger fibre diameter. Phosphate pretreatment had no influence on cooking loss, shear force and thiobarbituric acid reactive substance values of Tom Yum marinated muscle during storage. Tom Yum marination with phosphate pretreatment caused a higher increase in psychrophilic bacteria compared to that of marinating without phosphate. CONCLUSION Phosphate pretreatment could not improve the physical quality of Tom-Yum marinated spent hen muscle and affected the antimicrobial property of Tom-Yum marinade, resulting in a reduction of shelf-life of the marinated muscle from 30 days to 20 days.

Optimizing the electrical conductivity of marinade solution for water-holding capacity of broiler breast meat

Abstract This study explored the possibility of forecasting the performance of marinade solutions in improving the water‐holding capacity (WHC; weight gain, drip loss, cooking loss, and total yield) of marinated broiler breast meat based upon the electrical conductivity (EC) of the marinade solution. Normal‐ (50 ≤ L* ≤ 56) and light‐colored samples (L* > 56), obtained from a production line, were marinated with 1 to 6% sodium bicarbonate (NaHCO3), 0.5 to 3% sodium tripolyphosphate (STPP), 1 to 6% sodium chloride (NaCl), and 0.05 to 0.5% acetic acid (CH3COOH) solutions. EC of all solutions increased with increasing solute concentration, and high EC of any salt solution correlated with increased weight gain and decreased drip loss and cooking loss, leading to increased total yield. CH3COOH had the least effect on the WHC of marinated breast meat. The effect of increasing EC of marinade solutions on drip loss was similar in the light‐ and normal‐colored samples, but light‐colored samples consistently had higher cooking losses and lower total yields compared with the normal‐colored samples. At the same EC, NaHCO3 and STPP solutions had greater abilities to improve the total yield of marinated breast meat than the NaCl solution. Therefore, the WHC of the sample did not depend on the EC of the solution alone. However, increasing EC had a high correlation with gains in WHC of marinated breast meat for all marinade solutions (r > 0.96 for total yield). The total yield of both normal‐ and light‐colored samples of broiler breast meat could be improved to a value higher than 75% when samples were marinated in salt solutions with EC ≥ 8.79 mS/cm for NaHCO3 or ≥ 9.91 mS/cm for STPP. NaCl solutions with EC ≥70.08 and ≥44.58 mS/cm could be used to improve total yield to values higher than 75% for light‐ and normal‐colored samples, respectively. Our results revealed that EC could be used to forecast the performance of marinade solution in improving the WHC of marinated breast meat.

Effect of sugar and starch levels on electrical conductivity of marinade solutions in improving water-holding capacity of marinated broiler breast meat

SUMMARY Marinade solutions are used to improve the water‐holding capacity (WHC) of marinated meat. Previously, we found that the electrical conductivity (EC) of salt solutions had a high correlation with the WHC of marinated breast meat. However, marinade solutions, prepared using ingredients such as sugar and starch, might affect this correlation. In this study, we evaluated the effect of the different EC of mixed salt solutions, influenced by the level of the sugar (dextrose) and starch (waxy maize starch; WM starch), on WHC (determined as weight gain, drip loss, cooking loss, and total yield) of normal‐colored (50 ≤ L* ≤ 56) and light‐colored (L* > 56) chicken breast meats. The decrease in the EC of the mixed salt solutions was affected by the level of dextrose and WM starch; however, the WHC of breast meat, marinated with a mixed salt solution containing dextrose and WM starch, was increased. The EC and concentration of the mixed salt solution, containing dextrose, had a low correlation with the WHC of marinated breast meat. Interestingly, the cooking loss and total yield of marinated breast meat could be predicted using the concentration and EC of the marinade solution containing starch.

Effect of Heating Methods on Quality Attributes of Culled Saanen Crossbred Goat Meat

A series of 20 new biologically active derivatives of 2-{4, 5-(substituted diphenyl)-4H-1,2,4-triazol-3-ylthio}acetyl chloride has been synthesized, with the aim to investigate antimicrobial, free radical scavenging activity. All the synthesized compounds were characterized by spectroscopic data and elemental analysis. The final compounds were tested for antibacterial activity against Gram-positive bacteria: Staphylococcus aureus MTCC 3160, Bacillus subtilis MTCC 441; Gram-negative bacteria: Escherichia coli MTCC 443, and, for antifungal activity, against Candida albicans MTCC 227 and Aspergillus niger MTCC 281, taking ciprofloxacin as antibacterial and fluconazole as antifungal standard drugs. Compound 7a 6 was found to be the most effective antibacterial (MIC = 3.12 µg/ml), and compounds 7a 2 and 7d 1 (MIC = 3.12 and 6.25 µg/ml) had the most effective antifungal effects on the selected strains, as compared to the standard drugs. The results of antioxidant studies revealed that compound 7b 1 was found to be most active antioxidant, with 40.4±0.687 µg/ml, and compounds 7b 3 , 7d 7 , and 7d 4 also showed promising free radical scavenging activity, as compared with the standard drug ascorbic acid.

Imaging Analysis by Digital Camera for Separating Broiler Breast Meat with Low Water-Holding Capacity

Separating breast meat with low water-holding capacity, conformation parameters (thickness, volume, bottom sarea, and perimeter), and color of chicken breast meat were measured by direct measurement and by imaging analysis with a digital camera. Samples were obtained from a production line. The L* value was used to separate the samples by three characteristics designating the quality of the meat: dark-colored samples (L*<50), normal-colored samples (50≤L*≤56), and light-colored samples (L*>56). Light-colored samples had higher moisture content, thawing loss, drip loss, and lower pH compared with those of normal- and dark-colored samples. Lower thickness was observed in the light-colored samples compared with those of normal- and dark-colored samples. Light- and normal-colored samples had a greater volume of meat than did the dark-colored samples. Imaging analysis showed that light-colored samples had a greater bottom area and perimeter compared with those of normal- and dark-colored samples. However, these conformation parameters showed low correlation with water-holding capacity, which was determined as thawing and drip loss of the samples. Therefore, the conformation parameters, determined by direct measurement or imaging analysis, could not be used to predict the water-holding capacity of breast meat. Nevertheless, waterholding capacity showed high correlation with the L* value of breast meat. Imaging analysis could be used to separate light-colored breast meat with mostly low water-holding capacity. The accuracy of determining the characteristics of light-, normal-, and dark-colored samples by imaging analysis was evaluated. The characteristics of light-colored samples were determined with higher accuracy by imaging analysis than were the characteristics of normal- and dark-colored samples. This result indicated that imaging analysis using a digital camera could be used to separate light-colored breast meat with mostly low water-holding capacity from normal- and dark-colored meat.