Microbial Population and Shelf Life Study of Spiced Water Melon Juice (Published)
The microbial quality of spiced watermelon juice and the effect of pasteurization on the juice were investigated. Watermelon juice samples were analyzed according to standard bacteriological methods. The present study indicated significant reduction in microbial activities in all the juice samples under review. However, the rate of decline in the samples was less in refrigerated samples as compared to that stored at ambient temperature. The result for aerobic mesophilic count for the different watermelon juice samples increased (unpasteurized) from 3.22 × 102 to 5.31 × 102 cfu/ml, while the pasteurized watermelon juice samples showed a decreased microbial load from 0.05 × 102 to 0.07 × 102 cfu/ml. Results pre and post pasteurization of the juices showed zero (0) count for mould and E.coli, while total coliform ranged from <3.0 × 102 to 9.0 × 102 for the pasteurized and unpasteurized samples (MPN Index). 0Brix for all the samples showed a decreasing trend, with the control (sample E) having the highest brix value. As storage progressed over a period of four week, brix values were higher at refrigerated temperature than at room temperature storage for all the samples. Refractive index decreased with storage at room temperature for all samples but remained relatively stable at refrigeration temperature. The pH of samples decreased with storage and time over a period of four weeks, with the spiced samples having lower pH values, while total titratable acidity (TTA) increased over the same period. The study revealed that the combined effect of spice, pasteurization and refrigeration positively affected the shelf life of the juice samples.
Keywords: Juice, Microbial Analysis, Shelf-Life, Water Melon
Extraction and Evaluation of Hydrocolloids from “Achi” (Brachystegia eurycoma) and its Application on a Water Melon Fruit Juice (Published)
Hydrocolloid was extracted from dehulled “achi” (Brachystegia eurycoma) seed with the aim of evaluating its functionality as a food stabilizing ingredientin fruit juice industries. The “achi” seeds were sorted, cleaned, milled into flour and defatted to extract the hydrocolloid (food gum) from it, after which the functional properties were analyzed. 3g of the extracted hydrocolloid was added to 300ml of water melon fruit juice. To compare its effect with other conventional hydrocolloids, Guar gum and Arabic gum were also added to the same quantity of water melon fruit juice. Viscosity analysis was carried out at four different temperatures of 40oC, 50oC, 60oC and 70oC.The result showed that the extracted hydrocolloid from “achi” seed had a swelling index of 3.67%, a wettability of 43minutes and 23 seconds, and a bulk density of 0.82. There was a decrease in the apparent viscosities of Guar gum, Arabic gum and “achi” hydrocolloid as well as the control water melon fruit juice samples as the temperature increased. Although, it was observed that the melon fruit juices with different hydrocolloids showed that the juice with Arabic gum had the highest mean viscosity value of 56, 54.8 and 52 at 40oC, 50oC and 60oC respectively while Guar gum had the highest mean value of 22 at 70oC. So, the “achi” hydrocolloid can compete favorably with other hydrocolloids or food gums in the fruit juice industry.
Keywords: Water Melon, achi, fruit juice, hydrocolloid and Functional properties.
Microbial Population and Shelf Life Study of Spiced Water Melon Juice (Published)
The microbial quality of spiced watermelon juice and the effect of pasteurization on the juice were investigated. Watermelon juice samples were analyzed according to standard bacteriological methods. The present study indicated significant reduction in microbial activities in all the juice samples under review. However, the rate of decline in the samples was less in refrigerated samples as compared to that stored at ambient temperature. The result for aerobic mesophilic count for the different watermelon juice samples increased (unpasteurized) from 3.22× 102 to 5.31 × 102 cfu/ml, while the pasteurized watermelon juice samples showed a decreased microbial load from 0.05 × 102 to 0.07 × 102 cfu/ml. Results pre and post pasteurization of the juices showed zero (0) count for mould and E.coli, while total coliform ranged from <3.0 × 102 to 9.0 × 102 for the pasteurized and unpasteurized samples (MPN Index). 0Brix for all the samples showed a decreasing trend, with the control (sample E) having the highest brix value. As storage progressed over a period of four week, brix values were higher at refrigerated temperature than at room temperature storage for all the samples. Refractive index decreased with storage at room temperature for all samples but remained relatively stable at refrigeration temperature. The pH of samples decreased with storage and time over a period of four weeks, with the spiced samples having lower pH values, while total titratable acidity (TTA) increased over the same period. The study revealed that the combined effect of spice, pasteurization and refrigeration positively affected the shelf life of the juice samples.
Keywords: Juice, Microbial Analysis, Shelf-Life, Water Melon