Kanitha Tananuwong

Chemical compositions, functional properties, and microstructure of defatted macadamia flours

The objective of this research was to study the chemical compositions, functional properties, and microstructure of partially defatted flours (PDF, 12-15% fat, dry basis (db)) and totally defatted flours (TDF, 1% db fat) from three macadamia cultivars, PY 741, DS 344, and DS 800, grown in Northern Thailand. The defatted flours were high in protein (30.40-36.45% db) and carbohydrate (49.29-57.09% db). For each macadamia cultivar, while emulsion activities and emulsion stabilities of the TDF tended not to be different from those of the PDF (p>0.05), TDF had significantly greater water absorption capacities (WAC), oil absorption capacities and foaming capacities (FC), but had significantly lower foaming stability (FS) than the PDF (p⩽0.05). The TDF from PY 741 cultivar possessed the highest WAC and FC but the lowest FS. The variation in the functional properties of the defatted flours could mainly arise from the difference in the quantity and characteristics of the proteins in the flours. Structure determination of macadamia flours showed that the proteins bodies and starch granules were embedded in kernel tissues. The starch granules were oval and approximately 10μm in diameter.

Changes in volatile aroma compounds of organic fragrant rice during storage under different conditions.

BACKGROUND Aroma of fragrant rice greatly affects palatability as well as consumer acceptability. Loss of desirable volatile compounds such as 2-acetyl-1-pyrroline (2-AP) and increase in volatile lipid oxidation products in aged rice have been reported. The aim of this study was to monitor the changes in key volatile compounds of organic red fragrant rice cv. Hom Daeng during storage. Effects of packaging material, storage temperature and time were evaluated using solid phase microextraction/gas chromatography/mass spectrometry. RESULTS Thirteen key volatile compounds including ten lipid oxidation products were monitored. For samples vacuum packed in Nylon/LLDPE pouches at ambient temperature, significant increases in hexanal, 2-pentylfuran, 1-octanol and 4-vinyl guaiacol and significant decreases in 2-AP and geranyl acetone were found after the second month (P< or =0.05). Vacuum packing in OPP/Al/LLDPE pouches or storage at 15 degrees C better retarded the formation of volatile lipid oxidation products and greater retained desirable odorants, including 2-AP. However, accumulation of lipid oxidation products and 4-vinyl guaiacol was apparent after the sixth month under these storage conditions. CONCLUSION A greater extent and higher rate of undesirable changes in volatile compounds were found in samples stored under Nylon/LLDPE/ambient temperature condition. Nevertheless, this condition is acceptable for the retail trade of organic rice in Thailand. Storage conditions using reduced temperature or better packaging materials may be more appropriate for exported rice or superior-grade fragrant rice to better maintain the desirable rice aroma.

Effects of High‐Pressure Processing on Inactivation of Salmonella Typhimurium, Eating Quality, and Microstructure of Raw Chicken Breast Fillets

UNLABELLED High-pressure inactivation of Salmonella Typhimurium DMST 28913, eating quality, and microstructure of pressurized raw chicken breast meat was determined. The inoculated samples (approximately 7 log CFU/g initial load) were processed at 300 and 400 MPa, using pressurized medium of 25 to 35 °C during pressurization. Weibull model was well fitted to the survival curves with tailing. Least severe conditions with acceptable inactivation levels were 300 MPa, 35 °C, 1 min (approximately 2 log reduction) and 400 MPa, 30 °C, 1 min (approximately 4 log reduction). Based on these 2 conditions, the 400 MPa treatment yielded the raw chicken meat with higher L* value, greater cooking loss, and lower water holding capacity. Cooked chicken breast meat prepared from the pressurized samples had firmer texture than the control. Scanning electron microscopic images showed that higher pressure resulted in increasing extent of protein coagulation and the contraction of the muscle bundles. PRACTICAL APPLICATION For raw chicken breast fillet, 300 MPa, 35 °C, 1 min was the condition that reasonably reduced the load of Salmonella Typhimurium. However, the pressurized samples had greater cooking loss. Marination with brine containing sodium chloride and phosphate prior to pressurization might help improve this eating quality.

Development of non-water soluble, ductile mung bean starch based edible film with oxygen barrier and heat sealability

This research determined the effects of starch concentration (3.5-5.0%w/w), and plasticizer [glycerol (0-30%w/w) or sorbitol (0-60%w/w)] on properties of mung bean starch (MBS) films. The result showed that increasing plasticizer concentration tended to decrease tensile strength (TS), elastic modulus (EM) and oxygen permeability (OP); but increase elongation (%E), solubility, water vapor permeability (WVP) and seal strength. The extent of those changes also depended on starch concentration. Glycerol provided better plasticizer efficiency than sorbitol. A bimodal melting endotherm of retrograded structure was evident in non-plasticized film. However, only a low temperature endotherm was observed in polyol-plasticized films, indicating a plasticizer-induced structural modification. The developed ductile MBS films, (TS of 7.14±0.95 to 46.30±3.09MPa, %E of 2.46±0.21 to 56.95±4.34% and EM of 16.29±3.40 to 1428.45±148.72MPa) with an OP of 0.2397±0.0365 to 1.1520±0.1782 ccmm/m2daykPa and seal strength up to 422.36±7.93N/m, demonstrated in this study indicate the potential for food packaging applications.

Storage stability of packaged baby formula in poly(lactide)-whey protein isolate laminated pouch

BACKGROUND The use of biodegradable polymeric materials has been proposed as an environmentally-friendly alternative to petroleum-based packaging. To extend the shelf life of food products, these bioplastics must possess appropriate barrier properties and food-package stability. In the present study, shelf life analysis of packaged baby formula in biopolymeric, multilayer film, fabricated from poly(lactide) (PLA) and whey protein isolate (WPI), PLA/WPI/PLA and PLA pouches was performed at 4-35 o C and 50-59% relative humidity. RESULTS Despite the possible sorption of food components into contact PLA surfaces, the results demonstated that the transparency and barrier properties of PLA-based pouches were insignificantly changed over time (P > 0.05), although the films showed a slow rate of color change. The baby formula packaged in PLA/WPI/PLA had a delayed lipid oxidation compared to the sample in the PLA pouch, especially at a higher temperature. The application of WPI in the multilayer structure shifted the shelf life determination factor from lipid oxidation to moisture gain. CONCLUSION The results indicate that the PLA/WPI/PLA pouch has good storage stability. The film could be used to package dry food properly at 4-35 o C and 50-59% relative humidity for an extended period of time.

Aging kinetics of low amylose rice during storage at ambient and chilled temperatures

ABSTRACT The objectives of this study were to monitor the changes in rice properties during aging and to compare kinetic parameters related to some of those changes. Paddy of three low amylose rice varieties was stored at ambient (30 ± 2ºC) and chilled (8 ± 2ºC) temperatures for 9 and 18 months, respectively. Aging led to a decrease in solid loss, peak viscosity, breakdown, and adhesiveness and an increase in head rice yield, minimum cooking time, water uptake, volume expansion, pasting temperature, final viscosity, through viscosity, setback, and hardness. Low temperature storage efficiently retarded those changes. Data of the time-dependent changes in hardness, adhesiveness, pasting temperature, peak viscosity, and breakdown of all samples stored at 30°C were fitted well with the first-order fractional conversion kinetic model (R2 = 0.77 – 0.98). Higher storage temperature resulted in greater rate constant (k; up to 9 times higher) of those changes.

Macadamia Flours: Nutritious Ingredients for Baked Goods

Publisher Summary Macadamia is a tree nut indigenous to Australia, whose kernels can be processed into a wide variety of products, such as nut snacks, oil, and flours. Macadamia kernels are good sources of proteins, dietary fibers, vitamins, and minerals. Defatted or reduced-fat macadamia flours obtained as by-products of macadamia oil production can be nutrient-rich ingredients for foods and beverages. This chapter provides a review of the production and nutritional quality of macadamia nuts and flours. Details on functional aspects as well as possible applications of macadamia flours in food products are also provided. A limited amount of lysine is a significant problem in using macadamia flours as potential protein sources. A limited amount of lysine is a significant problem in using macadamia flours as potential protein sources. Mixtures of macadamia flours and other lysine-rich flours are thus recommended as ingredients for protein fortification in baked goods. A higher degree of lipid extraction improves functional properties, including water and oil absorption capacities and foaming capacity, of macadamia flours. Due to their outstanding functional properties, macadamia flours may be used to replace egg and dairy ingredients, as well as to enhance the texture and flavor of baked goods.