Effect of Fish Proteins, Salt, Sugar and Monosodium Glutamate on the Microstructural, Rheological and Physico-Chemical Properties of Fish Cracker ('Keropok')

Fish cracker or more commonly known as 'keropok' in Malaysia is a popular snack food among countries in the ASEAN region. This work examines factors affecting 'keropok' quality such as the effect of fish proteins, salt. sugar, monosodium glutamate (MSG) on the gelatinisation of tapioca and sago st arches. Microstructural studies of 'keropok' during different stages of processing were al so observed and correlated to rheological behaviour. Results from differential scanning calorimetry (DSC) showed that with increasing fish content the conclusion gelatinisation temperature (Tc) of the mixture remained relatively constant while the range of gelatinisation temperature decreased. There were hardly any effect due to the addition of 1% sugar and 0.4% MSG. on the onset (To) and peak(Tp) gelatinisation temperatures of sago and tapioca starches. The addition of 2% salt had the greatest effect on gelatinisation temperature of 'keropok' mixture, linear expansion of fried'keropok',and small and large deformations of 'keropok' gel. The technology of producing a good expanded 'k that fresh fish, sufficient amount of salt (2% of the total weight of wet fish and starch), proper sequence of mixing of the 'keropok' mixture to form evenly distributed fiexpansion, full gelatinisation of fish-starch gel, and elastic fish-starch gel formation. At high fish contents (60-70%) the formation of fish protein network in the matrix caused a drop in expansion. There was, however, a sharp increase in the compressive strength of the 'keropok' gel. This result is complemented by the higher storage modulus (G') and lower loss tangent (tan ᵟ) values obtained, indicative of the existence of a strong elastic network. Such conditions were observed when the microstructure of the fish muscle fibres appeared to be well crosslinked. The findings in this study revealed that in order to produce better expanded 'keropok' and a more elastic and fully gelatinised 'keropok' gel, superior interms of appearance, shape and linear expansion, several important factors that ensure even distribution of fish proteins in the fish-starch gel must be taken into account. In conclusion, fresh fish, sufficient amount of salt (2% of the weight of wet fish and starch) and the proper sequence of adding ingredients in mixing are recommended to produce high quality ' keropok'

Preparation of dipalmitin by fractionation method / Normah Ismail, Cheow Chong Seng and Chong Chiew Let

Dipalmitin was prepared by glycerolysis of palmitic acid in the presence of isooctane and Lipozyme RM 1M and was further purified by neutralization followed by fractionation. Dipalmitin containing samples was named as ‘diacylglycerol chemical method’ (DGCHM). The dipalmitin content in DGCHM was 71.83%, however, after fractionation, this percentage was raised to 89.80%. The DGCHM and RBDPO (refined bleached and deodorized palm oil) added with DGCHM were analysed for their crystallization behavior. The complete melting temperature for DGCHM was 70.7°C. The combined DSC and wide-angle XRD of the dipalmitin revealed the polymorphic transformation from α to sub α to α. The yield for DGCHM was 71% (w/w). The purification of dipalmitin by fractionation method was considerably practical due to the higher yield, easier preparation, shorter preparation time and smaller amounts of starting materials required. The addition of 1% DGCHM to RBDPO has a negligible effect on its crystallization and heating properties

Effect of different degree of deacetylation, molecular weight of chitosan and palm stearin and palm kernel olein concentration on chitosan as edible packaging for cherry tomato

The palm stearin and palm kernel olein (PSPKOo) blend (at 31%) was incorporated into chitosan of different degree of deacetylation (DD) (85 and 95%) and molecular weight (MW) (100,000 and 300,000 Da) to form films, and the films were evaluated in terms of particle size, diameter and stability of emulsion, as well as thickness and tensile strength. The chitosan with 85% DD (MW 300,000 Da) and 31% PSPKOo blend resulted in the strongest film, while this chitosan varied with 15.5 and 31% of PSPKOo blends compared to physical properties of film. Emulsion blend containing 85% DD (MW 300,000 Da) and 31% PSPKOo blend of chitosan gave the biggest particle size, highest viscosity and the most stable emulsion, resulting in the thickest film with the highest tensile strength (TS) and elastic modulus (EM). The film was applied on cherry tomato and stored at 20C for 9 days. The chitosan film with 85% DD (MW 300,000 Da) and 31% PSPKOo blend was the most effective in reducing weight loss and maintaining firmness and redness of cherry tomato compared to the other two films. Hence, palm stearin (PS) showed potential to be used as a moisture barrier in fruit coating

Detecting outliers beyond tolerance limits derived from statistical process control in patient-specific quality assurance

Tolerance limit is defined on pre-treatment patient specific quality assurance results to identify "out of the norm" dose discrepancy in plan. An out-of-tolerance plan during measurement can often cause treatment delays especially if replanning is required. In this study, we aim to develop an outlier detection model to identify out-of-tolerance plan early during treatment planning phase to mitigate the above-mentioned risks.Published versionThis work was funded by Academic Program Goh Foundation Proton Research Programme, Grant/Award Number:08/FY2022/EX(SL)/125-A187