No abstract

Purpose -This study aims to focus on the use of pectinase enzymes for producing clarified mango juice with blend of orange juice and to evaluate some of its quality attributes. Design/methodology/approach -Mango pulp was incubated at 60 o C for 1 hr to destroy natural enzymes present in the juice. Prepared mango pulp and separately prepared orange juice were formulated into various mixes in the ratio mango:orange (v/v) 100:0, 50:50 and 0:100. A portion of the mango pulp or the one with equal volume of orange was then treated with 0.1 per cent (v/w) pectinase enzymes at 40 o C for 24 hrs. All the treated and untreated mixes were separately packed inside a bottle and pasteurized at 80 o C for 10 mins. Samples were analyzed using methods reported in the literature for some chemical and sensory properties. Findings -From this project work, the use of enzyme (pectinase) in juice production from mango was found beneficial and profitable since it increases the yield of juice extracted. A blend of mango and orange juice which was processed with enzyme was found not to be significantly different from orange juice in terms of sweetness, appearance, flavour and general acceptability. Originality/value -The paper has demonstrated effect of pectinase enzymes in the production of clarified mango juice with blend of orange juice and its acceptability.

The purpose of this study was to investigate the effect of different levels of Pseudomonas fluorescens (10 2 and 10 6 log 10 cfu/ml) and Lactobacillus plantarum (10 2 and 10 4 log 10 cfu/ml) on the growth of Escherichia coli O157:H7 on beef loins. Beef loins inoculated with E. coli O157:H7 and P. fluorescens were aerobically stored for 7 days at 4 ºC, while those inoculated with E. coli O157:H7 and L. plantarum were vacuum packaged and stored for 8 weeks at 4 ºC. Aerobic Plate Counts (APC), E. coli O157:H7 and either P.fluorescens or L. plantarum counts were determined at different storage intervals. For the aerobically packaged beef loins, E. coli O157:H7 was detected throughout the 7 day storage period regardless of the P.fluorescens level in the inoculum. For the vacuum packaged beef loins, similar inoculum levels of E. coli O157:H7 and L. plantarum allowed E. coli O157:H7 to survive until week 5 of storage, while a higher inoculum level of L. plantarum inhibited E. coli O157:H7 from week 3. Once fresh beef has been contaminated with E. coli O157:H7, the level of P. fluorescens in the background flora does not inhibit its survival and growth. However, under vacuum storage, the application of L. plantarum as a biopreservative inhibits the survival of E. coli O157:H7 on beef. The higher the level of L. plantarum in the system, the earlier the onset of the inhibition. Farmers and abattoirs have to strengthen preventive strategies to eliminate contamination of beef carcasses with E. coli O157:H7.