Aneet Kaur

Molecular characterization and enzymatic hydrolysis of naringin extracted from kinnow peel waste

Kinnow peel, a waste rich in glycosylated phenolic substances, is the principal by-product of the citrus fruit processing industry and its disposal is becoming a major problem. This peel is rich in naringin and may be used for rhamnose production by utilizing α-L-rhamnosidase (EC 3.2.1.40), an enzyme that catalyzes the cleavage of terminal rhamnosyl groups from naringin to yield prunin and rhamnose. In this work, infrared (IR) spectroscopy confirmed molecular characteristics of naringin extracted from kinnow peel waste. Further, recombinant α-L-rhamnosidase purified from Escherichia coli cells using immobilized metal-chelate affinity chromatography (IMAC) was used for naringin hydrolysis. The purified enzyme was inhibited by Hg2+ (1 mM), 4-hydroxymercuribenzoate (0.1 mM) and cyanamide (0.1 mM). The purified enzyme established hydrolysis of naringin extracted from kinnow peel and thus endorses its industrial applicability for producing rhamnose.

Approaches to Agro-industrial Solid Waste Disposal and Bioenergy Generation

Increasing concern about the environment, food and feed shortages, and hike in the price of petroleum has stimulated interest in the new ways of producing more bioenergy. The interest is rapidly increasing toward converting agricultural and industrial wastes to commercially valuable products. Waste disposal and pollution are inextricably linked. Unwanted residues that are usually perceived to be of negative value are described as waste. The production of citrus juice on an industrial level leads to a considerable quantity of solid and liquid residue (8–20 million tons year−1), which is considered as waste. Citrus processing residues possess no economic value. They are rich in soluble sugars, cellulose, hemicellulose, pectin, and essential oils that could form the basis of several industrial processes. Possible applications of these waste residues include fertilizer, cattle feed, charcoal, adsorption of chemical compounds, bioethanol production, and extraction of essential oils and pectin.