Use of Pineapple Fruit Juice as a Technology for Softening of Oak Tasar Cocoons

Abstract

Oak tasar cocoons are difficult to reel due to the presence of high amounts of protein-tannin complexes. The chemical methods developed for reeling these cocoons is not readily adopted by the common tasar silk reelers and weavers due to various reasons including relatively low reeling performance, low fuel efficiency, complicated procedure and prolonged cooking time. Proteolytic enzymes that cleaves the internal peptide bonds in an amino acid chain have the potential to effect partial solubilisation of the proteinaceous silk gum (sericin) involved in biding the silk (fibroin) strands together in silkworm cocoon, an essential step in the silk cocoon cooking and reeling. Pineapple fruit extract rich in cysteine endopeptidases has a potential application in cooking and reeling of oak tasar (Antheraea proylei J.) silk cocoons which cannot be softened by boiling in plain water unlike the mulberry cocoons (Bombyx mori L). The experimental results from the present investigation on the oak tasar cocoon cooking with pineapple extract at room temperature and subsequent study have indicated for an applicability of pineapple extract as an effective agent for the oak tasar (Antheraea proylei J.) cocoon cooking and reeling. It is observed that enzymatic cocoon cooking has advantages over chemical method. The method involving pineapple extract is a relatively better method regarding its overall better reeling performances and also mostly due to the abundant availability of pineapples grown in the oak tasar belt in India. Moreover, the method is environmentally friendly and is readily accessible to the common tasar silk reelers and weavers.