RESUMEN
The ready-to-drink (RTD) tea beverages are becoming increasingly popular owing to the health benefits associated with tea polyphenols, but instability due to development of haze and formation of tea cream is a common problem encountered in the product. Membrane technology provides a scope to produce natural, additive-free RTD teas while overcoming the major disadvantages associated with the conventional decreaming methods. Approaches employing membranes for the clarification of extracts from black and green tea have been discussed together with their relative advantages and limitations. The article also outlines the concerns to be addressed in the future attempts employing membrane technology.
Asunto(s)
Tecnología de Alimentos/métodos , Membranas Artificiales , Té/química , Antioxidantes , Camellia sinensis , Hidrolasas de Éster Carboxílico , Catequina , Estabilidad de Medicamentos , Filtración , Manipulación de Alimentos/métodos , Promoción de la Salud , Humanos , Extractos Vegetales/química , PolifenolesRESUMEN
Ready-to-drink (RTD) tea is a popular beverage in many countries. Instability due to development of haze and formation of tea cream is the common problem faced in the production of RTD black tea beverages. Thus decreaming is an important step in the process to meet the cold stability requirements of the product. Enzymatic decreaming approaches overcome some of the disadvantages associated with other conventional decreaming methods such as cold water extraction, chill decreaming, chemical stabilization, and chemical solubilization. Enzyme treatments have been attempted at three stages of black tea processing, namely, enzymatic treatment to green tea and conversion to black tea, enzymatic treatment to black tea followed by extraction, and enzymatic clarification of extract. Tannase is the most commonly employed enzyme (tannin acyl hydrolase EC 3.1.1.20) aiming at improving cold water extractability/solubility and decreasing tea cream formation as well as improving the clarity. The major enzymatic methods proposed for processing black tea having a direct or indirect bearing on RTD tea production, have been discussed along with their relative advantages and limitations.
Asunto(s)
Bebidas , Hidrolasas de Éster Carboxílico , Manipulación de Alimentos/métodos , Té/química , Camellia sinensis , Precipitación Química , Frío , Estabilidad de Medicamentos , Enzimas Inmovilizadas , Fermentación , Extractos Vegetales , Hojas de la Planta/química , Polifenoles/metabolismo , Solubilidad , AguaRESUMEN
Tamarind seed is an underutilized byproduct of the tamarind pulp industry. Only a small portion of the seed, in the form of tamarind kernel powder (TKP), is used as a sizing material in the textile, paper, and jute industries. Though many applications of this seed are possible, there have been hardly any other uses for it including using it as an additive in food formulations. The excellent gelling cum adhesive characteristics of the decorticated seed powder can lead to several applications in food and pharmaceutical industries which are evident by the number of research papers as well as patent applications. This article thus focuses on the possibilities of using the seed in several food and non-food industries with particular reference to physical and engineering properties, hydration behavior, rheological properties, functional and nutritional characteristics, and the processing of the tamarind seed for wider applications.
Asunto(s)
Semillas , Tamarindus , Fenómenos Químicos , Química Física , Industria Farmacéutica , Aditivos Alimentarios , Industria de Alimentos , Glucanos , Residuos Industriales , Industrias , Valor Nutritivo , Papel , Semillas/química , Semillas/ultraestructura , Industria Textil , XilanosRESUMEN
In vitro antioxidant activities of three selected Indian red seaweeds - viz., Euchema kappaphycus, Gracilaria edulis and Acanthophora spicifera were evaluated. Total phenolic content and reducing power of crude methanol extract were determined. The antioxidant activities of total methanol extract and five different solvent fractions (viz., petroleum ether (PE), ethyl acetate (EA), dichloromethane (DCM), butanol (BuOH) and aqueous) were also evaluated. EA fraction of A. spicifera exhibited higher total antioxidant activity (32.01 mg ascorbic acid equivalent/g extract) among all the fractions. Higher phenolic content (16.26 mg gallic acid equivalent/g extract) was noticed in PE fraction of G. edulis. Reducing power of crude methanol extract increased with increasing concentration of the extract. Reducing power and hydroxyl radical scavenging activity of E. kappaphycus were higher compared to standard antioxidant (alpha-tocopherol). The total phenol content of all the seaweeds was significantly different (P<0.05). In vitro antioxidant activities of methanol extracts of all the three seaweeds exhibited dose dependency; and increased with increasing concentration of the extract.