MICROBIAL EXAMINATION OF MOULD AND YEAST IN FRUIT JUICES

Abstract

Fruit juices consists of water, carbohydrates, protein, lipids, acids, phenolics, dietary fibre and pigments that play a vivacious part in human nutrition, as they supply vitamins and essential minerals which are necessary growth factors in human diet and that can assist in maintenance of a good and healthy life. However due to their short shelf life these juices either glass bottles, plastic bottles, paper cups and plastic cups or unpacked can be contaminated by micro flora (especially mould and yeast) and can become a source of health hazard. Hence current study was focused to examine the diversity of mould and yeast contaminants in different types of packed and unpacked fruit juices (pH ranges from 3.35 to 4) of six different localities of Lahore such as Chouburji, Govt College of Science, Mozang, Muslim Town, Shadman and Iqbal town. The fungal contaminants (mould and yeast) isolated from their respective juices were cultured on malt extract agar as well as on potato dextrose agar under sterilized conditions. Serial dilution technique was used to compose the replicates in order to get viable count of micro flora in juices samples. Results indicated that in case of packed juices, the maximum fungal viable count was found in samples of Shadman (10x10-4 to 14x10-5 cfu/ml) while minimum was found in Chouburji samples (2x10-4 to 5x10-3 cfu/ml). The highest mould (803000 cfu/ml) in packed juices was found in locality of Mozang, but lowest value was observed in samples obtained from Muslim town i.e., 16000 cfu/ml. However, yeast contaminants were found in great concentrations in Shadman samples (71000 cfu/ml) and least count was found in locality of Iqbal town i.e., 200000 cfu/ml. For unpacked (fresh) juices the peak value of fungal viable count was observed in Shadman (8x10-5 to 14x10-5 and 18x10-5 ) while minimum was found in GCS (4x10-4 to 7x10-3 ). The uppermost value of mould count (1800000 cfu/ml was also observed in locality of Shadman and least mould (25000 cfu/ml) in unpacked juices was found in locality of GCS. Whereas maximum yeast i.e., 400000 cfu/ml was detected in locality of Shadman and least one 11000 cfu/ml was reported in Chouburji. Reported fungal species were Aspergillus niger, Aspergillus terreus, Penicilium digitatum, Curvularia americanna, Fusarium moniliforme, Alterneria alternate and Saccharomyces cerevisae. Results indicated that mould and yeast (fungal) count is much more standard tolerable range (102 to 103 cfu/ml) hence this negligence and unawareness can lead to serious health damage of consumers