Effect of different drying techniques on chemical composition, color and antioxidant properties of kinnow (Citrus reticulata) peel.

Aim of the present study was to evaluate the effect of different drying techniques on chemical composition, color and antioxidant activity of kinnow peel. Fresh peel was dehydrated by three different techniques (tray, vacuum and freeze) and regardless of the method results showed significant decreases in moisture, total phenols, flavonoids, antioxidant activity and color when compared to the fresh sample. Freeze drying was found superior in retention of polyphenolic characteristics and color attributes when compared with other drying techniques. The fresh and freeze-dried citrus peel extract was analyzed for individual phenolics and flavonoids with the help of HPLC indicating highest concentrations of ferulic acid and hesperidin.

Antioxidant and antimicrobial potential of selected varieties of Piper betle L. (Betel leaf).

Piper betle L., is an evergreen perennial creeper belonging to family Piperaceae and is known to possess numerous medicinal properties. Current study focuses on evaluating antioxidant and antimicrobial potential of betel leaf. For the present study, distilled water, hexane, acetone and ethanolic extracts of two varieties of betel leaves: Meetha paan and Banarasi paan were used. Biochemical tests such as proximate analysis (moisture, ash, protein, lipids, minerals viz., sodium and potassium), antioxidant activity tests (DPPH radical scavenging activity, total phenolics, ascorbic acid, reducing power) and antimicrobial test (antibacterial and antifungal susceptibility test) against four pathogens viz., B. subtilis, E. coli, A. niger and S. cerevisiae were determined. Ethanolic extract had the highest antioxidant activity (89.46% inhibition), while the aqueous extract exhibited lowest antioxidant activity (62.03% inhibition). With increasing concentration (5, 10, 25 and 50 µg/mL), the reducing power of leaf extracts also increased. The ascorbic acid was not significant in Banarasi paan (5.21mg/100 g) and Meetha paan (5.20mg/100 g). The highest antibacterial activity of ethanolic extract (Banarasi paan) may be attributed to the presence of phytosterols in the leaf varieties. Antioxidant and antimicrobial potential study will help to build a database and promote the utilization of betel leaf as a medicinal herb.

Effect of extrusion on thermal, textural and rheological properties of legume based snack.

Attempts have been made to improve dough handling properties and quality of legume based snack by incorporating extruded black gram (EBG) flour as partial substitute for raw black gram (RBG) flour. In present work overall quality improvement was achieved by analyzing (a) thermal properties of RBG and EBG flour (b) rheological properties (shear stress, shear rate, storage modulus, loss modulus, deflection angle and complex viscosity) of legume based snack dough and (c) post frying characteristics (colour and texture) of legume based snack. Three different legume based snack samples with different flour formulations (RBG flour, RBG flour incorporated with 25% EBG flour and RBG flour incorporated with 50% EBG flour) were prepared, characterized and compared with standard market sample. Dough exhibited shear thinning behaviour and G' and G″ showed rising behaviour with angular frequency whereas, complex viscosity showed decreasing behaviour. Herschel-Bulkley model was best fitted. Significant changes were observed in values of onset, peak and endset gelatinization temperatures on extraction of black gram flour which improved dough handling properties during papad processing and enhanced organoleptic profile of end product.

Use of paprika oily extract as pre-extrusion colouring of rice extrudates: impact of processing and storage on colour stability.

Suitability of paprika oily extract as a pre-extrusion colouring of rice extrudate was evaluated as a function of extrusion parameters viz. moisture content, screw speed and die temperature. Most acceptable coloured rice extrudates in terms of colour and overall acceptability was achieved with addition of 3 % paprika oily extract and which is extruded at fixed conditions of 25 % feed moisture, 120 °C barrel temperature and 100 rpm screw speed. During extrusion, retention of red colour of paprika oily extract added rice extrudates increased with an increase in feed moisture and screw speed while decreased with an increase in barrel temperature. Present study was also undertaken to check effect of addition of butylated hydroxytoluene (BHT) on colour stability of coloured rice extrudates. Coloured rice extrudates were packed in polyethylene, metallised polyethylene and vacuum packaging material and subjected to storage studies for 90 days at 25 and 50 °C with 65 % relative humidity conditions. Retention of red colour (a*) of paprika oily extract added rice extrudates follows first order kinetics, showing a faster rate of degradation with half-life of 48 days when packed in metalized polyethylene and stored at higher temperature conditions.

Effect of extrusion process parameters and pregelatinized rice flour on physicochemical properties of ready-to-eat expanded snacks.

Present study was conducted to investigate effects of pregelatinized rice flour and extrusion process parameters such as feed moisture (16-19 %), die temperature (115-145 °C) and screw speed (150-250 rpm) on physicochemical properties of ready-to-eat expanded snacks by using co-rotating twin-screw extruder. Higher die temperature increased extrudate density and WSI but reduced die pressure, torque and expansion. Increased feed moisture content resulted in extrudates with increased density, WAI and hardness but reduced die pressure, expansion and WSI. Screw speed was found to have no significant effect on expansion and hardness of extrudates, while increase in screw speed resulted in increased WAI of extrudates and reduced torque of extrudates. Effect of pregelatinized rice flour on extrudate expansion and hardness was analysed at 16 % feed moisture, 135 °C die temperature and 150 rpm screw speed. Use of pregelatinized rice flour increased expansion while it reduced hardness of extrudates.

Application of ultrasonication as pre-treatment for freeze drying: An innovative approach for the retention of nutraceutical quality in foods.

Freeze drying (FD) is an important and highly effective technology in food industry for retaining the quality in final dried product. This drying technique is performed at lower temperatures, restricting the damage suffered by thermally sensitive ingredients. However, FD consumes large amount of energy and required more time than conventional drying methods. The utilization of ultrasonic technology (US) as pre-treatment before FD represents a promising alternative in accelerating the drying process, decreases energy consumption and maintaining quality as compared to the non pre-treated sample. This review summarizes research progress and current studies in ultrasonic as pre-treatment for freeze drying (US + FD) technique. The impact of US + FD on phytochemical, color, texture and micro-structure of food are well summarized. The review also suggests that the optimised US treatment parameters are required to improve heat and mass transfer in food samples which help in speed up the drying process and reduction of drying time.

Bioactive characterization and optimization of Tamarindus indica seed protein hydrolysate: technology and application of natural enzymes.

Tamarind seeds are one of the major sources of different nutrients and minerals and are used as antioxidant components in various food products. Bioactive peptides are released by enzymatic hydrolysis of major food proteins followed by different separation techniques to isolate them from the mixture of other components. Further incorporation of bioactive peptides in various food products may lead to more diversification, fulfilling different nutritional requirements, and promoting health benefits. The objective of this study was to optimize the parameters for the formation of tamarind protein hydrolysates with the use of pepsin and trypsin. It was observed that pepsin and trypsin derived hydrolysate showed the maximum degree of hydrolysis and other bioactive characteristics (DPPH activity, reducing power, ABTS activity, and antidiabetic activity) under optimized conditions. High-performance liquid chromatography was performed for amino acid profiling on trypsin derived protein hydrolysate. From this study, pepsin and trypsin derived hydrolysate can be considered as a rich source of natural antioxidants for developing food formulation.

Bioactive compounds of beetroot and utilization in food processing industry: A critical review.

Beetroot is recognized as health promoting food due to presence of essential components such as vitamins, minerals, phenolics, carotenoids, nitrate, ascorbic acids and betalains that promote health. Betalains occur in two forms i.e. betacyanin (red-violet pigment) and betaxanthin (yellow-orange pigment) and are recognizable commercially as a food dye due to non-precarious, non-toxic, non-carcinogenic and non-poisonous nature. Beetroot is premeditated as a boon for the food industry and used as food colorant or additive in food products such as ice-cream, yogurts and other products. The beetroot extract is used to improve the redness in tomato pastes, soups, sauces, desserts, jams, jellies, sweets and breakfast cereals. Overall objective of this review is to provide a brief knowledge about the valuable phytochemicals and bioactive compounds present in beetroot and their association with health benefits, beetroot processing for food application and their effect on beetroot pigment.

Bioactive compounds and pharmacological and food applications of Syzygium cumini - a review.

The present review explores the nutritional, phytochemical and pharmacological potential as well as diverse food usages of Syzygium cumini. S. cumini is a traditional medicinal plant with various bioactive compounds distributed in all parts of the plant. The major bioactive compounds present in the edible part are myricetin, oxalic acid, gallic acid, citronellol, cyanidin diglucoside, hotrienol, phytosterols, flavonoids, carotenoids and polyphenols as well as micronutrients, accounting for numerous health benefits. The potential benefits of these bioactive compounds are to prevent/reduce metabolic abnormalities and various diseases. The health protective effects and functional properties of the plant were proved by different in vitro and in vivo pharmacological studies. All parts of the plant have good health benefits like hypoglycemic, anti-inflammatory, antianemic, antibacterial, antioxidant, antiallergic, hepatoprotective, hypolipidemic and antipyretic properties. The fruit of S. cumini can be consumed raw or processed in the form of jam, jellies, wine, fermented beverages and many other value added food products.

Citrus medica: nutritional, phytochemical composition and health benefits - a review.

Citrus medica (Citron) is an underutilized fruit plant having various bioactive components in all parts of the plant. The major bioactive compounds present are iso-limonene, citral, limonene, phenolics, flavonones, vitamin C, pectin, linalool, decanal, and nonanal, accounting for several health benefits. Pectin and heteropolysachharides also play a major role as dietary fibers. The potential impact of citron and its bioactive components to prevent or reverse destructive deregulated processes responsible for certain diseases has attracted different researchers' attention. The fruit has numerous nutraceutical benefits, proven by pharmacological studies; for example, anti-catarrhal, capillary protector, anti-hypertensive, diuretic, antibacterial, antifungal, anthelmintic, antimicrobial, analgesic, strong antioxidant, anticancerous, antidiabetic, estrogenic, antiulcer, cardioprotective, and antihyperglycemic. The present review explores new insights into the benefits of citron in various body parts. Throughout the world, citron has been used in making carbonated drinks, alcoholic beverages, syrup, candied peels, jams, marmalade, cordials, and many other value added products, which suggests it is an appropriate raw material to develop healthy processed food. In the present review, the fruit taxonomical classification, beneficial phytochemicals, antioxidant activities, and health benefits are discussed.

Microbial maceration: a sustainable approach for phytochemical extraction.

A rapid change in the lifestyle has witnessed poor health with the increased incidences of numerous diseases in the recent years, and ultimately increasing the demand of nutritious foods containing phytochemicals. A wide range of phytochemicals (secondary metabolites) is being synthesized in plants, which influence the human health upon consumption as dietary component. Recently, a number of the technologies (conventional and non-conventional methods) have been standardized by the different researchers for the extraction of these phytochemicals depending upon the raw material. However, selection of extraction method for commercial use depends upon various factors such as extraction efficiency, time required, and cost of operation. Considering these factors, microbial maceration is one of the viable approaches which is easy to handle, cost-effective, energy efficient, less hazardous and having high extraction rate. Recently, researchers have utilized this technique for the maceration of different plant-based substrates (such as legumes, cereals, pulses, fruits and vegetables) and their respective wastes for the efficient extraction of numerous phytochemicals with increased efficiency. However, scale up studies and analysis of toxic compounds produced by microbes are still a lacking field and need to be explored further by the researchers and industrialists to bring it into reality. Therefore, the present review aims to document the recent findings related to microbial maceration in a crisp way to provide the complete information to the readers.

Development of functional fermented whey-oat-based product using probiotic bacteria.

The aim of the present study was to formulate a fermented whey product using probiotic bacteria and whey protein concentrate (WPC containing 70% of proteins) to obtain a fermented product with low lactose and ß-lactoglobulin (BLG) content. Several factors such as starter culture concentration (1, 5, and 10%) and fermentation time (2, 4, 6, 8, and 10 h) were optimized on the basis of growth activity in terms of viable count, pH, and acidity. Starter culture concentration and fermentation time of 5% and 10 h, respectively, show the optimal viable count (9.8 × 1010) and pH (4.42) as per the requirement. Proteolysis of WPC by a mixed culture of Lactobacillus acidophilus and Lactobacillus bulgaricus was found to be 98.8 µg/ml. Hydrolysis of whey proteins by probiotic bacteria was detected by SDS-PAGE. A significant (p ≤ 0.05) decrease in cell viability and pH was observed as the refrigerated storage period goes on increasing (0-15 days).

Use of microalgal biomass as functional ingredient for preparation of cereal based extrudates: impact of processing on amino acid concentrations and colour degradation kinetics

Abstract Suitability of developing Spirulina incorporated cereal based low cost nutritious extrudates was analysed against extrusion processing parameters. Most significant extrusion processing parameters considered for present study were feed moisture (20-25%), die temperature (100-120 °C) and screw speed (50-100 rpm). Different extrusion conditions were used to obtain most acceptable rice: Spirulina blend extrudates. In present study before extrusion processing different additives (citric acid and sodium bicarbonate) were added in rice: Spirulina blend and checked its effect on colour degradation kinetics at varied packaging and storage conditions. Higher screw speed (100 rpm) indicating less residence time of feed material inside the barrel resulted in higher colour retention of rice: Spirulina (97:03) blend extrudates. Kinetics for rice: Spirulina (97:03) blend extrudates indicates faster rate of colour degradation in terms of lightness (half-life of 4 days) when packed in metalized polyethylene at 50°C with 65% relative humidity. Increased concentration of Spirulina (1-3%) in raw formulations resulted in increase in concentration of all amino acids. Impact of extrusion processing has shown non-significant (p ≤ 0.05) effect on amino acid concentrations of rice: Spirulina blend extrudates. Also, all the spirulina added samples showed good consumer acceptability with the score of 6.7