Potential of non-thermal processing for food preservation in Southeast Asian countries

The application of non-thermal processing technology (NTP) is increasing within the food industry. The absence of heat in this technology offer some advantages such as the sensory and nutritional attributes of the product remaining unaffected, thus yielding products with better quality compared to traditional processing methods. Suitability of technology for a certain application varies according to the nature of the reason and the purpose for processing. Some NTP has long been used in the food industry in Southeast Asia, but most are still at the initial stage of research. Despite several existing challenges, these technologies have the potential to be taken up as an alternative to processing of value-added food products especially now when consumer and trade demands as well as economic strength in the region is changing

Pulsed light treatment as an alternative technology to extend shelf life of fresh-cut yardlong bean (Vigna unguiculata)

Pulsed light (PL) treatment is a non-thermal method for microbial decontamination on the surfaces of fresh-cut produce. The effect of pulsed light fluencies on microbiological stability and quality changes of fresh-cut yardlong beans were determined. Pulsed light treatments were carried out using an automatic laboratory flash lamp system (Steribeam XeMaticA-2L Kehl, Germany) at different fluencies (1.8 J/cm2, 5.4 J/cm2, 9.0 J/cm2 and 12.6 J/cm2). Microbiological quality (colour changes and textural changes) of fresh-cut yardlong beans stored at 4±1°C were monitored over 14 days. Results show that, the application of PL treatment at high fluencies allowed extension of microbiological shelf life up to 3-7 days in comparison to untreated samples. Apart from that, PL treated sample has no significant difference on the texture and colour as compared to untreated sample of fresh-cut yardlong bean. As a conclusion, the application of PL at dose 9.0 J/cm2 has increased the shelf life of fresh-cut yardlong bean while maintaining the quality when stored at 4±1°C

Effect of gamma radiation on reduction of mycotoxins in black pepper.

Gamma ray was applied to reduce mycotoxins, i.e. ochratoxin A (OTA) and aflatoxins B1, B2, G1 and G2 (AFB1, AFB2, AFG1 and AFG2) in black pepper. Response surface methodology (RSM) was applied to evaluate the effect of dose of gamma ray ranging from 0 to 60 kGy and mycotoxin concentration ranging from 10 to 100 ng g−1 on the mycotoxin reduction. The maximum reduction was found at 60 kGy which was 52%, 43%, 24%, 40% and 36% for OTA, AFB1, AFB2, AFG1 and AFG2, respectively. Results showed the gamma rays even at 60 kGy were not effective in completely destroying of ochratoxin and aflatoxins

Performance of UV pasteurization with quartz glass sleeve on physicochemical properties and microbial activity of pineapple juice

Quartz glass has characteristics of high purity, high thermal resistance, high resistivity and high dielectric strength. Currently, majority of research in this area is discussing about the UV reactor equipped by a quartz glass sleeve. The aim of this research is to investigate the effect of quartz glass sleeve on the physicochemical properties and microbial activity of pineapple fruit juice during storage. UV-C radiation is one of the nonthermal technologies that have been introduced in the food industry. UV-C has the advantage of no known toxic or significant nontoxic by-products formed during treatment. The UV reactor that is enclosed by quartz glass can maintain the quality of pineapple juice in terms of color (L* value, chroma and hue angle), total soluble solids, pH and ascorbic acid content. All of the physicochemical properties of pineapple juice underwent significant changes with storage time. Moreover, the UV reactor that is enclosed by quartz glass is able to extend the shelf life of juice for up to 5 weeks and achieve a 5 log reduction of Salmonella typhimurium in the juice after treatment

Effects of UVC irradiation and thermal treatment on the physico-chemical properties and microbial reduction of clear and turbid tamarind juice

Tamarind juice is commonly treated with thermal treatment to inactivate microorganisms. However, thermal treatment deteriorates the appearance and flavor of tamarind juice. In this study, the performance of UVC treatment on clear and turbid tamarind juice as an alternative to thermal treatment was investigated. Results showed that UVC treatment was able to reduce E. coli O157:H7 by 7-log reduction but unable to completely remove the total bacterial population as observed in thermally treated clear and turbid tamarind juices. The pH of treated tamarind juices was comparable to each other. Nonetheless, UVC treatment caused significant changes on the flavor of the juice as it significantly reduced the total soluble solids of tamarind juices and decreased the titratable acidity of turbid tamarind juice. However, UVC treatments retained the appearance i.e. turbidity and color of tamarind juices better than thermal treatment

Ranking of endurance horses in training based on some selected biochemical and physical parameters

Objective: This study aims to appraise the ranking of endurance horses in training based on some selected biochemical and physical parameters. The increase in skill and gusto in equine endurance sport demands an upsurge in standardized exercise tests and competition to be enforced on endurance sport horses. Materials and methods: Nine seemingly fit Arabians endurance horses between the ages of 5 and 17 years and with a body weight of 350 and 450 kg were included in the research in Malaysia. We designed a point scale in training based on biochemical and physical parameters of endurance horses for lactate, plasma protein, creatine kinase, heart rate, and rectal temperature. Results: The results indicated an accumulated lower point of 1 for the biochemical and physical parameters for an individual horse to have an excellent ranking in training and placing in endurance race contrasted with horses that had higher points of 4 to 6. The lower the points, the lower will be the values of the parameters and the higher the points the higher will be the values of the parameters. It is observed that placing in race tally with the ranking in training. Conclusion: In conclusion, it is observed that placing in race tally with the ranking in training. Therefore, it is suggested that the current ranking system in training could be valid to be used to predict endurance horses performance in an actual race

Effect of heat treatment on the physico-chemical properties of starch from different botanical sources

Changes in the physicochemical properties of wheat, sago, tapioca and potato starches were studied after heating for 1 hour at 100°C, 110°C, and 120°C and for 2 hours at 120°C. These properties were characterised through the swelling behaviour of starch granules, amount of carbohydrate materials leached from the granules, starch paste retrogradation rate and gel strength. For all starches except wheat, the swelling ability, rate of retrogradation and gel strength decreased while solubility increased with increasing temperature and heating time. Wheat starch followed this pattern only when heated at 120°C for 1 and 2 hours. Gel strength correlated well with the ratio of amylose to amylopectin (R) in the leachate. To produce fried crackers with good expansion properties, the granule has to be sufficiently degraded so as to allow more amylopectin to be leached out to achieve R value of 0.25-0.5. This can be achieved by heating wheat starch at 120°C for 1 hour or longer

Microwave-assisted extraction of pectin from jackfruit rinds using different power levels

Pectin is a heterogeneous branched polysaccharide with complex structure. Microwave-assisted extraction (MAE) is more efficient in extracting pectin compared to conventional method. The objective of this study was to compare the efficiency of microwave-assisted pectin extraction against conventional extraction method. This study was also to investigate the effect of power level on yield and quality of extracted pectin from jackfruit rinds. Water-based extraction method was performed with the extraction duration for conventional extraction and MAE were 1 h and 10 min, respectively. The temperature of conventional extraction was set at 90°C and the power levels of MAE were 450 W, 600 W and 800 W. High yield of pectin was obtained from conventional extraction (14.59%) and MAE (16.72-17.63%). All quality characteristics determined were found to be insignificant different for pectin extracted from both conventional extraction and MAE except moisture and ash content. Increase in microwave power did not affect yield and quality characteristics of pectin from jackfruit rinds significantly. In conclusion, MAE requires shorter time than conventional extraction in extracting comparable amount and quality of pectin from jackfruit rinds. Microwave-assisted extraction at 450 W was the most effective and economic extraction condition among the different power levels tested

Dimension and stackability of cassava (Manihot esculanta Crantz) chips for mass production

Cassava chips that exist in the current market have no standardisation and cannot be stacked nicely into cylindrical container. The objectives of this work are to determine the different dimension of cassava chips produced with different thickness and to develop stackable chips during mass production. Fresh cassava tubers were harvested, washed, peeled and sliced. The thickness measurements used were 1.0 mm, 1.5 mm, 1.75 mm and 2.0 mm and 1.27 mm thickness was measured from commercial potato chips as a controlled sample. Then, it was fried in deep fat fryer with the temperature of 170°C. For each thickness studied, different numbers of slice (10, 20, 30 and 40 slices) were fried simultaneously. Results showed that there are 6 shapes of fried chips produced during the frying. To conclude, thickness of the slice and number of slices fried simultaneously give impact towards the shape of fried chip

Quality changes of fresh cut cantaloupe (Cucumis melo L. var Reticulatus cv. Glamour) in different types of polypropylene packaging

Consumers today prefer to purchase ready-to-eat, fresh-cut fruit that is readily available at the markets and retailers. They generally select the fresh-cut fruit base on the quality, freshness, nutrition and safety. The effects of packaging condition on fresh-cut Cantaloupe were studied during 18 days of storage at 2°C and 87% RH. Fresh-cut Cantaloupe pieces were packed in a Polypropylene (PP) container. As a control, the container was cover with lid without film, while Sample 1 (S1) was sealed only by a 40 μm PP film and Sample 2 (S2) was sealed with a 40 μm PP film and then adding the lid cover. Changes in colour, firmness Total Soluble Solids (TSS), pH, Titratable Acidity (TA) and Total Plate Count (TPC) were evaluated over time. During storage, it was found that the firmness significantly decreased from day 0 until day in all packaging conditions. Color parameters Luminosity (L*) and Chromaticity (C) were significantly change at the significance level of 95% (p<0.05) while hue angle (hab) were not significant (p<0.05) change for all types of packaging. Meanwhile, pH, Titratable Acidity (TA) and Total Plate Count (TPC) were significantly changed over time at the significance level of 95% (p<0.05). The fresh cut cantaloupe packed with the control method showed better appearance and quality as compared to the other treatments after 18 days of storage. These results suggest that the PP container with a lid cover only (control) is suitable to be used for fresh cut cantaloupe during the first 18 days of storage at 2°C