The chemical nature of the polyphenols of cashew kernel testa has been determined. Testa contains tannins, which present large molecular complexity and has an ancient use as tanning agents. The use of tannins extracted from cashew testa, considered in many places as a waste, grants an extra value to the cashew. In this work we have analysed through high performance liquid chromatography, infrared spectroscopy (FT-IR) and thermo gravimetric analysis the average molecular weight, main functional groups and thermal properties of tannins extracted from Anacardium occidentale L. The results of these analyses are compared with the commercial grade tannic acid. The FT-IR spectra showed bands characteristic of C = C, C-C and OH bonds. This important bioactive compound present in the cashew nut kernel testa was suggested as an interesting economical source of antioxidants for use in the food and nutraceutical industry.

Econazole is an imidazole derivative antifungal drug with distinguished antifungal properties. But the bioavailability of conventional econazole preparations is poor because of poor solubility and lipophilicity or lipophilic nature. Thus frequent application of the preparation is required to maintain therapeutic levels at the site of action. Such repeated doses may produce toxic affects thereby limiting the clinical use of the drug. Citric acid dendrimers give an opportunity to overcome the above limitations by improving its solubilization and drug permeation properties. Thus, the aim of current study is to design citric acid dendrimer hydrogels and study its influence on the drug release and anti-fungal activity of loaded drug. Dendritic architecture and size strongly influences the invitro release and antifungal activity of drug. Antifungal activity of designed Econazole hydrogel was measured by Agar plate diffusion method. Zone of inhibition values showed that citric acid dendrimers considerably enhanced the antifungal activity of Econazole to a greater extent and the effect was more with lower generation hydrogels. The operative mechanism is probably the smaller size (G2) that penetrates the fungal cell membrane more efficiently than higher generation (G3 and G4) hydrogels.

The use of better carbon sources and efficient production strains were deemed as promising strategies to economize tannase production. A novel agro-residue, cashew testa, was tested for the production of tannase under solid-state fermentation (SSF) using Aspergillus niger CEPC 11. CEPC 11 was identified by 18S rDNA typing as Aspergillus niger and deposited in International depositing Authority under MTCC number 5898 and NCBI accession number KM516789. The enzyme was purified 11 fold to obtain tannase with a specific activity of 10.22 U/mg and final yield of 48 %. SDS-PAGE analysis of purified enzyme gave a single band of 89.9KDa. The optimal temperature was found to be 40°C, with an active range of 25-60°C. The optimal pH was 5.5, and the enzyme was inactive at pH 8.0. The enzyme was identified through MALDI-TOF-MS tandem mass spectrometry as tannase. Km and Vmax were recorded at 0.1133 M (substrate concentration) and 44.79 μmol/min respectively. Heavy metals (Cadmium, Nickel, Lead, and Copper) in tannery effluent were analyzed before and after treatment with enzyme by AAS (Atomic Absorption spectroscopy). Gallic acid is also determined as an inter-mediatory by-product of this technology. Treatment with tannase enzyme improved the quality of fruit juices. This is the first report on production of tannase by Aspergillus niger under SSF with cashew industry by-product cashew testa as the substrate. The use of residues is an alternative to solve pollution problems that can be caused by an incorrect environmental disposal.

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