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a b s t r a c tThis study aimed to determine the prevalence and quantity of Salmonella spp., Salmonella Typhi and Salmonella Typhimurium in sliced fruits from hawker stalls and hypermarkets in Malaysia. Analysis was carried out using the most probable number (MPN) e multiplex polymerase chain reaction (PCR) method. The prevalence of Salmonella spp., Salmonella Typhi and Salmonella Typhimurium in 210 samples of sliced fruits examined were 23.3%, 7.6% and 3.8%, respectively with estimated quantity varying from 0 to 19 MPN/g. This study urged the authority to look into the biosafety of sliced fruits in Malaysia.

Salmonellosis outbreaks involving typhoid fever and human gastroenteritis are important diseases in tropical countries where hygienic conditions are often not maintained. A rapid and sensitive method to detect Salmonella spp., Salmonella Typhi and Salmonella Typhimurium is needed to improve control and surveillance of typhoid fever and Salmonella gastroenteritis. Our objective was the concurrent detection and differentiation of these food-borne pathogens using a multiplex PCR. We therefore designed and optimized a multiplex PCR using three specific PCR primer pairs for the simultaneous detection of these pathogens. The concentration of each of the primer pairs, magnesium chloride concentration, and primer annealing temperature were optimized before verification of the specificity of the primer pairs. The target genes produced amplicons at 429 bp, 300 bp and 620 bp which were shown to be 100% specific to each target bacterium, Salmonella spp., Salmonella Typhi and Salmonella Typhimurium, respectively.

Enzymatic synthesis of medium-chain glycerides (MCG) from capric acid and glycerol was studied using lipase from Candida rugosa. The effects of various reaction parameters such as time, molar ratio of substrates (mmol capric acid/ mmol glycerol), amount of lipase, type of organic solvents, and initial water activity (a w ) were studied. The best conditions tested for MCG synthesis at 37°C were, respectively, time, 24 h; molar ratio of substrates, 2.5; and amount of lipase, 100.0 mg. The use of organic solvents greatly influenced the activity of lipase in the synthesis of MCG. Generally, activity of lipase was high in nonpolar solvents with log P values from 3.50 to 4.50, where P is the partition coefficient between water and 1-octanol. The enzymatic synthesis of MCG was preferably carried out at an initial a w of 0.328, which resulted in maximal yield. Analysis of the products of reaction using gas chromatography showed that lipase from Candida rugosa seemed to produce more dicaprin and tricaprin than monocaprin.Paper no. J9113 in JAOCS 77, 85-88 (January 2000).Medium-chain glycerides (MCG) are glycerides containing mono-, di-, and triglycerides of caprylic and capric acids (1). Their manufacture involves the hydrolysis of high-grade vegetable oils such as coconut oil, which is rich in medium-chain fatty acids, followed by the fractionation of the resulting fatty acids to concentrate caprylic and capric acids, and reesterification with glycerol to form glycerides. Medium-chain mono-, di-, and triglycerides have unique properties that make them attractive for use in cosmetics, toiletries, the pharmaceutical industry, and human nutrition. They are also used as a solvent or carrier for dyes, flavors, vitamins, and pharmaceuticals and to dissolve gallstones in humans (2). Industrially, MCG are produced by reacting medium-chain fatty acids and glycerol under elevated temperature and pressure; extensive product purification is required (1). An alternative method is the use of an enzyme as a catalyst whereby the reactions can be carried out at ambient temperature and pressure. The product obtained with an enzyme is usually much purer than that at higher temperatures and pressures.In this paper, the synthesis of MCG using capric acid and glycerol, an abundant by-product in the oleochemical industry in Malaysia, was carried out using lipase from Candida rugosa. The effects of various parameters on esterification reaction were investigated. EXPERIMENTAL PROCEDURESMaterials. Lipase from C. rugosa (Type VII) and capric acid were purchased from Sigma Chemical Co. (St. Louis, MO). Glycerol was obtained from BDH Supplies (Poole, England) and PORIM (Kuala Lumpur, Malaysia). All other reagents were of analytical grade.Esterification reaction. Glycerol (1.0 mmol), capric acid (3.0 mmol), hexane (3.0 mL), and lipase from C. rugosa (50.0 mg) were mixed in reaction vials. The mixture was incubated at 37°C for 16 h (unless otherwise stated) with continuous shaking at 150 rpm in a horizontal shaker waterbath. The reaction was terminate...

A total of 63 beef offal samples (beef liver = 16; beef lung = 14; beef intestine = 9; beef tripe = 15; beef spleen = 9) from three wet markets (A, B, and C) in Selangor, Malaysia were examined for the prevalence and microbial load of Listeria monocytogenes. A combination of the most probable number and polymerase chain reaction (MPN-PCR) method was employed in this study. It was found that L. monocytogenes detected in 33.33% of the beef offal samples. The prevalence of L. monocytogenes in beef offal purchased from wet markets A, B, and C were 22.73%, 37.50% and 41.18% respectively. The density of L. monocytogenes in all the samples ranged from < 3 up to > 2,400 MPN/g. The findings in this study indicate that beef offal can be a potential vehicle of foodborne listeriosis.