Antioxidant Activity in Pulp and Peel of Three Mango Varieties

The aim of the present study was to estimate the content of total polyphenols and flavonoids and to investigate in-vitro antioxidant potential of methanolic extracts of peel and pulp in three Indian mango varieties. Antioxidant activity was assessed using [2,2'-azino-bis(3-ethylbenzothiazoline-6-sulphonic acid)] ABTS+ assay, 2,2-diphenyl-1-picryl-hydrazyl (DPPH) assay, ferric-reducing ability of plasma (FRAP) assay, and phosphomolybdate assay for Total Antioxidant Capacity (TAC). Total phenolic and flavonoid content was also determined, and expressed in gallic acid equivalent (GAE) and quercetin equivalent (QE), respectively. Results of this study indicated that methanolic extracts of mango peel had significantly higher antioxidant activity compared to that of pulp (29.69 and 3.12), irrespective of the method or variety used. Free radical scavenging and antioxidant activity may be attributed to presence of phenolic (24.61mg GAE/g DM in the peel and 2.01mg GAE/g DM in the pulp) and flavonoid compounds (24.95mg QE/g DM in the peel and 16.15mg E/g DM in the pulp). Antioxidant activity determined by ABTS, DPPH and FRAP assays in mango peel was significantly higher than in the mango pulp (24.95 1.96mg TE /g DM, 23.68 versus 4.60mg BHA/g DM and 40.52 versus 2.781mg TE/g DM), respectively. Results for scavenging activity against DPPH were 96.18% for the peel and 23.86% for the pulp, while, free radical scavenging activity results using ABTS+ assay were 99.62% in the peel and 13.46% in the pulp. Our study justifies research in processing of mango peel into useful, functional food ingredients (powders or extracts)

Thin Layer Drying Study on Foamed Mango Pulp

Rosana G. Moreira, Editor-in-Chief; Texas A&M UniversityThis is a paper from International Commission of Agricultural Engineering (CIGR, Commission Internationale du Genie Rural) E-Journal Volume 9 (2007): Thin Layer Drying Study on Foamed Mango Pulp. Manuscript FP 06 024. Vol. IX. March, 2007

Food processing waste dewatering by electro-osmosis

Orsat, V., Raghavan, G.S.V. and Norris, E.R. 1996. Food processing waste dewatering by electro-osmosis. Can. Agric. Eng. 38:063-067. As a result of changing waste-handling technologies, many industrial food processing wastes now being fed to animals were once considered to be without economic value. Other factors which have increased the interest in wastes utilization as animal feed include increasing costs of disposal and transportation and increasing environmental restrictions. This has brought about the necessity of separating the solid waste from the liquid waste for potential reuse of both fractions. This study examines the use of pressure alone and pressure combined with an electric field for dewatering purposes. Separation trials were conducted at various combinations of pressure and electric current with three types of food wastes. The results indicated that combining an electric field with mechanical dewatering can increase the percent solids from 30 to 49% for brewer's spent grain (BSG), from 23 to 53% for apple pomace, and from II to 67% for vegetable waste. The dewatering improvement of combining an electric field to mechanical dewatering is of the order of 2 to 8% (increase in solids) depending on the applied electric field and the produce being dewatered. All separation trials yielded an energy consumption, per kilogram of water removed, considerably less when compared to thermal drying. Aujourd 'hui, avec les developpements technologiq ues dans Ie domaine du traitement et de la manutention des dechets, les residus de production de l'industrie alimentaire ont une valeur ajoutee et sont maintenant reutilises comme engrais ou aliments pour animaux. La reutilisation des dechets est amenee par I'augmentation des restrictions environnementales. Ceci amene la necessite de separer les fractions solides/liquides de la masse de dechets pour reutilisation potentielle des deux fractions. La presente etude examine une methode d 'extraction associ ant electro-osmose et pression mecanique. Plusieurs essais ont ete entrepris adifferents niveaux de pression et de courants electriques pour trois types de dechets. Les resultats obtenus indiquent que l'association de l'electro-osmose a une pression mecanique, peut augmenter Ie taux de solide du dcchet aplus de 50%, et ce, avec une fraction de la consommation d'energie qu'i1 en couterait si les dechets etaient traditionnelIement seches a l'air chaud. En effet, nos essais ont augmente Ie taux de solide de 30 a 49% pour la dreche de brasserie, de 23 a 53% pour Ie marc de pomme de meme qu 'une augmentation de II a67% pour des dechets maraichers

Optimisation of radio frequency assisted extraction of apple peel extract: Total phenolic contents and antioxidant activity

The objective of this study is to determine the optimum operating conditions of apple peel extraction process using a novel extraction method known as radio frequency assisted extraction (RFAE). Apple peel extract with the highest total phenolic contents and antioxidant activity is targeted in this study. RFAE is a green extraction method which operates based on the dielectric heating concept. Response surface methodology was employed for designing the experiment, analysing the effects and optimising the extraction conditions for RFAE of apple peel phenolic compounds. The effects of ethanol concentration (10 - 70 %), mixing speed (10 - 320 mL N2/min), solid to liquid ratio (0.002 - 0.02 g/mL) and RF power (200 - 400 W) on total phenolic compounds and DPPH radical scavenging activity efficiency were investigated in order to understand and improve the RFAE performance. All processing parameters exert significant effects on the total phenolic compounds and radical scavenging activity of the apple peel extract. The highest recovery of TPC with a value of 121.87 mg GAE/ g DW can be achieved if the extraction is performed using 42.67 % ethanol concentration, mixing speed of 320 mL N2/min, solid to liquid ratio of 0.0114 g/mL and power at 400 W. The maximum value of DPPH (94.54 %) can be achieved if the extraction is performed using an ethanol concentration, mixing speed, solid to liquid ratio and power of 37.33 %, 165 mL N2/min, 0.02 g/mL and 400 W

Modeling of heat and mass transfer for texture improvement in microwave boiled lentils

Paper presented at the 7th International Conference on Heat Transfer, Fluid Mechanics and Thermodynamics, Turkey, 19-21 July, 2010.Lentil is an excellent source of proteins and various micro nutrients such as vitamin A, potassium, B vitamins, and iron, and it provides fiber with no cholesterol and virtually no fat. Canadian red lentils were soaked in ambient water for different times ranging from 0-120 mins. The soaked lentils were boiled in a custom built microwave setup at 2450 MHz with different lentil to water ratio of I:I, I:1.5 and I :2 for different durations of 20 mins, 40 mins and I hour. The mechanism of heat transfer and the fluid dynamics during microwave boiling of lentils were investigated. An empirical diffusion model was developed based on the assumption that there was no significant change in the hound moisture content due to protein denaturation. The rheological parameters of the boiled lentils were measured and compared. The parameters of soaking time, power density and boiling time were optimised for microwave boiling of lentils for better rheological quality. The model fits the data well and can be used to tweak the microwave boiling process of lentils to obtain desirable results.ej201

Overview of new techniques for drying biological materials with emphasis on energy aspects

With increasing concern about environmental degradation, it is desirable to decrease energy consumption in all sectors. Drying has been reported to account for anywhere from 12 to 20% of the energy consumption in the industrial sector. Drying processes are one of the most energy intensive unit operations. There are a number of approaches to reduce energy consumption in dryers. This paper reviews some novel strategies used to decrease energy consumption in drying operations. Drying conditions can be modified or the drying equipments can be modified to increase overall efficiencies. Hybrid drying techniques can also be used, such as combining vacuum or convective drying with electro-technologies (microwave, radio frequency, infrared heating). There is much debate on how to define drying and energy efficiencies. Some techniques to determine these efficiencies can be misleading when the goal is to take a holistic approach to determining energy consumption

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Not AvailableDate fruit is a good source of bioactive compounds and natural sugar. It has the potential to be utilized as a substitute for added sugar. Although several forms of dates—such as fresh dates, date paste, and date syrup—are available in the market and used for different applications, free-flow date powder would be highly beneficial in improving shelf-life, ease of handling, and blendability with various foods prepared domestically and in industry. The objective of this study was to produce date powder in a pilot-scale spray dryer and determine its physicochemical qualities. Date powder was produced at eight processing conditions (2 carrier agents (maltodextrin (MD) and gum arabic (GA) × 2 inlet air temperature (150°C and 170°C) × 2 feedstock flow rates (25 ml/min and 40 ml/min))). To the carrier agent was added at 0.4 kg per 1.0 kg of date fruits (dry weight basis), and the feedstock to the spray dryer was prepared at 20% concentration. Date powder was obtained in all eight treatments. Color (L*a*b* values), moisture content, bulk density, wettability, solubility index, hygroscopicity, microstructure analysis (using scanning electron microscope (SEM)), and total phenolic compounds were determined for the spray-dried date powder. The physicochemical characteristics of date powder varied significantly with respect to the processing conditions. Although physical properties of date powder were significantly affected by the carrier agent, there was no difference in total phenolic compounds between date powders produced with MD and GA. An SEM study revealed that date powder produced with MD had smooth, regular-shaped spherical particles but with severe agglomeration. Date powder with GA had relatively smaller particles of irregular sphere with dented surfaces.Not Availabl