A novel technique for the preparation of curd (Dahi) by PVDF membrane-based strip

Preparation of curd at home is quite challenging as it requires skills like addition of proper amount of starter culture, maintenance and storage of inoculum for the preparation of good and consistent quality curd. The present work utilized bacterial attachment property of PVDF (Polyvinylidene fluoride) membrane to prepare a strip which can be dipped into milk for the preparation of consistent quality curd. Shelf-life of the strip is around 100 days. The strip prepared curd was well comparable with the curd prepared by the commercial inoculum based on their pH, % lactic acid, % syneresis and bacterial load. Strip of size 5 × 5 cm² was enough for preparation of 500 mL curd. It was proved by different analytical techniques like AFM, SEM and FTIR that PVDF was not having any leaching property during curd preparation. It can also be used in repeated contact with food products, as it is FDA (Food and Drug Administration) compliant and non-toxic. The curd strip has significant industrial relevance as it is a cost-effective alternative of any commercial inoculum (very expensive) and also meets the demand of consumers with the rising health awareness and busy lifestyles. Further, it is spillage proof, portable, ready-to-use.

The online version contains supplementary material available at 10.1007/s13197-021-05339-3.