​Effects of Starter Culture and Types of Bamboo Tubes on Microbiological and Shelf Life Characteristics of Buffalo Milk Banhor Chunga Doi- an Ethnic Product of India

Abstract

Background: The present research was undertaken to study the effects of yoghurt culture and bamboo tubes on the microbiological and shelf life attributes of curd prepared from buffalo milk in bamboo tubes (popularly known as “Banhor Chunga Doi” in Assam) under room temperature. Methods: Banhor Chunga Doi was prepared using Jati and Jatie Makal bamboo tubes. Starter culture was added and the tubes were kept in ambient room temperature. The shelf-life of the set products was ascertained by objective assessment of pH, titratable acidity and microbial load. Result: Amongst the 4 treatment groups, the samples of B(JB) i.e., Banhor Chunga Doi prepared from boiled and cooled buffalo milk and stored in tubes of Jati bamboo at room temperature for 5d showed the highest pH value of 4.01±0.011 with a corresponding least lactic acid content of 1.21±0.005%. Amongst the 2 control and 4 treatment groups, the highest mean TVC of 8.69 log10cfu/g±0.001 was enumerated in the samples of SC (JB) which might be due to the addition of the starter culture at the dose level of approximately 6.86 log10cfu/g in the beginning of the production process. The starter culture added samples [SC (JB) and SC (JMB)] showed an increasing TVC up to 3rd day of storage. Thereafter, the TVC of these samples decreased on 5th day. The lowest mean TVC of 4.38±0.003 log10cfu/g was noted in the samples of B (JMB) which is due to the thermal destruction of the contaminating microbes during boiling of the milk sample. The samples of the buffalo milk Banhor Chunga Doi that were not inoculated with the starter culture exhibited an increasing TVC from 1st to the 5th d of storage at room temperature. Over the storage period, none of the Banhor Chunga Doi samples either from the control or the treatment groups were found to possess coliform organisms, Escherichia coli, Salmonella, Shigella, Staphylococcus aureus, yeast and moulds. The shelf life of the end product was found to be good for consumption upto 5 days with gradual decrease in pH values and concomitant increase in titratable acidity in all the treatment groups.