No abstract

Commercially supplied chicken breast muscle was subjected to simultaneous heat and pressure treatments. Treatment conditions ranged from ambient temperature to 70 degrees C and from 0.1 to 800 MPa, respectively, in various combinations. Texture profile analysis (TPA) of the treated samples was performed to determine changes in muscle hardness. At treatment temperatures up to and including 50 degrees C, heat and pressure acted synergistically to increase muscle hardness. However, at 60 and 70 degrees C, hardness decreased following treatments in excess of 200 MPa. TPA was performed on extracted myofibrillar protein gels that after treatment under similar conditions revealed similar effects of heat and pressure. Differential scanning calorimetry analysis of whole muscle samples revealed that at ambient pressure the unfolding of myosin was completed at 60 degrees C, unlike actin, which completely denatured only above 70 degrees C. With simultaneous pressure treatment at >200 MPa, myosin and actin unfolded at 20 degrees C. Unfolding of myosin and actin could be induced in extracted myofibrillar protein with simultaneous treatment at 200 MPa and 40 degrees C. Electrophoretic analysis indicated high pressure/temperature regimens induced disulfide bonding between myosin chains.

Chitin can be found in animal source especially arthropods such as crustacean, mollusk and insect, as well as in plant source such as fungi. Chitosan is obtained from chitin after the acetyl group is removed from chitin structure through deacetylation step and has wide application in various fields (food, cosmetics and pharmaceutical). In this study, chitosan was extracted from razor clam shells, where the extraction conditions were optimized. Two- factors of randomized D-optimal design was used to determine the optimum condition for the extraction of chitosan from razor clam (Ensis arcuatus) by using response surface methodology (RSM). The chemical extraction was optimized using five levels with two factors which were the deacetylation time (2,4,6,8,10 hrs) and deacetylation temperature (50, 60, 70, 80 and 90ºC). A randomized design suggested by Design Expert software was implemented with four responses evaluated: yield (%); degree of deacetylation (%); molecular weight (kDA); and ash content (%). Time (h) and temperature (ºC) of the deacetylation significantly (p<0.05) affected the yield (%), degree of deacetylation (DDA) (%), molecular weight (Mw) (kDA) and ash content (%) of the chitosan extracted. The optimum conditions for the chitosan extraction were at the respective deacetylation time and temperature of 6h and 70ºC with actual values of yield (%), degree of deacetylation (%), molecular weight (kDA) and ash content (%) of 19.903±2.367, 50.113±0.902, 476.727±13.603, 8.517±2.094, respectively. The optimum condition for the chitosan extraction was experimentally verified and valid for further analysis.

Ciku fruit (Manilkara zapota), also known as sapodilla is an exotic tropical fruit commonly eaten by Malaysians but not as popular as durians, rambutans, and bananas. Due to the short period of storage of ripened ciku fruits, making or converting it to a new end product such as pastille may promote the utilization and promote this tropical climate fruit and provide a wide range of products. Therefore, the purpose of this study was to develop ciku pastille and determine the physicochemical properties and sensory characteristics of ciku pastilles. A total of six formulations of ciku pastille were developed based on the different amounts of ciku purée (10%, 12%, 14%, 16%, 18% and 20% of ciku purée) added. The pastilles were analysed for their texture profile analysis (TPA), water activity (Aw), total soluble solids (TSS), colour analysis, pH, moisture content, ash, fibre and antioxidative activity. Results showed that formulation F (20% ciku purée) illustrated the highest value for moisture (18.59%), ash (2.43%), fibre (2.65%) and scavenging activity (36.58%). The production of this product is highly likely to be commercialised as no synthetic preservatives and artificial colouring were used. The ciku pastille was successfully developed with brownish-orange colour, round-shaped with a diameter of 1.0-1.2 cm, weighing approximately 1.2-1.5 g. Formulation B (12% ciku purée) has 62.7⁰ Brix with pH 4.3, which had an acidic aftertaste and a water activity of 0.54. For colour analysis, L* value (59.76), a* value (23.71) and b* value (34.33) brought the brownish-orange colour for ciku pastille. Formulation B (12% ciku purée) was highly accepted by the panellists and retained its good texture and colour after being kept in the chiller for 2 months at below 18°C. The analysis, therefore, revealed that the physicochemical properties of the ciku pastille produced were enhanced and found to be rich in antioxidants and accepted by the panellists. Ciku fruit may consequently be a possible natural ingredient for pastille production, thus promoting its use in the food sector.

Keropok lekor a fish-based sausage is a popular traditional food item in Terengganu state, Malaysia. This study aimed to develop a new flavor and taste of keropok lekor. Common spices such as cumin, coriander, cinnamon, cardamom, bay leaf, nutmeg, clove, onion, ginger, garlic were used to develop a new flavor of keropok lekor. A total of 5 samples, including two original and three developed keropok lekor samples were prepared. This study also evaluated the proximate composition of two raw samples (Original and developed). The results of the proximate analysis showed a significant difference (p<0.05) in all parameters except the fiber content. Hardness, springiness, and chewiness of the samples were measured by using TA-XTplus texture analyzer. There was a significant difference in the hardness level between original and developed sample. Finally, sensory evaluation according to six attributes such as color, odors, texture, flavor, taste and overall acceptability was done by 39 panelists. A 7-point hedonic scale ranging from “dislike very much” to “like very much” was employed in sensory testing. There was a significant difference (p<0.05) in all the sensory parameters evaluated. The results showed that most of the respondents preferred the developed samples over the original samples. Developed fried keropok lekor with bread crumb was the most acceptable one.