Compuestos antioxidantes y su bioaccesibilidad in vitro de la zanahoria (Daucus carota): cambios por procesos térmicos

La zanahoria (Daucus carota) pertenece a la familia de las Umbelíferas, es un vegetal rico en β-carotenos y otros antioxidantes. El objetivo de la revisión fue analizar el efecto del procesamiento térmico de la zanahoria sobre los compuestos antioxidantes y su bioaccesibilidad. Los tratamientos térmicos varían de acuerdo a las condiciones de temperatura y tiempo a los que son sometidos los alimentos. Investigaciones han reportado la aplicación de tratamientos térmicos en zanahoria como hervido, pasteurización, ultrapasteurización, esterilización comercial, escaldado, cocción a presión y freído. Existen cambios significativos en los parámetros de color cuando las zanahorias son escaldadas, los valores de a* y b* disminuyeron respecto a las muestras no tratadas. El contenido de compuestos fenólicos y su bioaccesibilidad se reduce con el escaldado y la pasteurización. La zanahoria Egmont Gold tratada a 80°C incrementó la concentración de ácido ascórbico (318.82±18.40 µg/g ps (peso seco)) en 23.84%, respecto a la muestra a temperatura ambiente (258.12±32.56 µg/g ps), debido a la inactivación de la enzima ácido ascórbico oxidasa. La cocción a presión (5134.5±75.3 µg/100 g pf (peso fresco)), hervido (6740.3±58.6 µg/100 g pf), freído (5926.4±106.6 µg/100 g pf), escaldado (87.70±2.75 µg/g pf) y secado (882-1079 mg/kg masa seca) de la zanahoria, provocó una disminución de carotenoides (2.53-31.58%). Por el contrario, cuando se analizó la bioaccesibilidad in vitro, la cocción a presión, hervido y freído incrementaron la bioaccesibilidad de los carotenoides (29.80%, 25.45% y 38.47%, respectivamente) en comparación con la zanahoria sin tratami The carrot (Daucus carota) belongs to the Umbelliferae family, is vegetable rich in β-carotenes and other antioxidants. The aim of the review was to analyze the effect of thermal processing of carrot on antioxidant compounds and their bioaccessibility. The thermal treatments vary according to the temperature and time conditions to which the food is subjected. Researchers have reported the application of thermal treatments to carrots such as boiling, pasteurization, ultra-pasteurization, commercial sterilization, blanching, pressure cooking and frying. There are significant changes in the colour parameters when the carrots are blanched, the values ​​of a* and b* decreased with respect to the untreated samples. The content of phenolic compounds and their bioaccessibility decreased with the blanching and pasteurization. Egmont Gold carrot treated at 80°C increased the concentration of ascorbic acid (318.82 ± 18.40 µg/g dw (dry weight)) by 23.84%, with respect to the sample at room temperature (258.12 ± 32.56 µg/g dw), due to the inactivation of the enzyme ascorbic acid oxidase. Pressure cooking (5134.5 ± 75.3 µg/100 g fw (fresh weight)), boiled (6740.3 ± 58.6 µg/100 g fw), frying (5926.4 ± 106.6 µg/100 g fw), blanched (87.70 ± 2.75 µg/g fw) and drying (882-1079 mg/kg dry mass) of the carrot, caused a decrease in carotenoids (2.53-31.58%). On the contrary, when was analyzed the in vitro bioaccessibility, pressure cooking, boiling and frying increased the bioaccessibility of carotenoids (29.80%, 25.45% and 38.47%, respectively) compared to carrots without treatment (16.80%), this behaviour also occurs in pasteurized, sterilized, ultra-pasteurized and dehydrated carrot pulp. However, the bioaccessibility of carrot antioxidant compounds depends on the polysaccharides of the cell membrane, proteins and other factors of the food matrix. ento (16.80%), este comportamiento también ocurre en la pulpa de zanahoria pasteurizada, esterilizada, ultrapasteurizada y deshidratada. Sin embargo, la bioaccesibilidad de los compuestos antioxidantes de la zanahoria depende de los polisacáridos de la membrana celular, proteínas y otros factores de la matriz alimentaria.

The effect of pre-drying treatments on the quality of dehydrated ground beef

Dehydrated ground meat is widely used as an ingredient in various instant products. This study was aimed to investigate the effect of pre-drying treatments on the physicochemical properties of dehydrated ground beef. The experimental design used a completely randomized design of 3 x 3 factorial, with 3 grinding times (1, 3, and 5 minutes) and 3 cooking methods (steaming, pressure cooking/presto, and roasting). The beef was sliced, milled and cooked according to the treatments, frozen for 24 h, then dried by using an oven drier at a constant temperature of 60°C for 3 h, and finally powdered. The physicochemical properties of dried ground beef were determined including the yield, particle size distribution, rehydration ratio, hygroscopicity, color, moisture content, and fat content. Results showed that the presto method produced the highest moisture content of the cooked beef. Longer grinding time increased the particle passed mesh-6, rehydration ratio, and color, but decreased the final moisture content and fat content. Grinding time of 5 minutes with pressure cooking was selected as the best treatment to prepare dried ground meat. This treatment had a yield of 22.26%, moisture content of 3.38%, rehydration ratio of 3.25, the hygroscopicity of 6,13%, lightness of 53.62, value ‘a’ of 5.52, value ‘b’ of 10.21, and fat of 6.36%.

Vitamins in Cereals: A Critical Review of Content, Health Effects, Processing Losses, Bioaccessibility, Fortification, and Biofortification Strategies for Their Improvement

Around the world, cereals are stapled foods and good sources of vitamins A, B, and E. As cereals are inexpensive and consumed in large quantities, attempts are being made to enrich cereals using fortification and biofortification in order to address vitamin deficiency disorders in a vulnerable population. The processing and cooking of cereals significantly affect vitamin content. Depending on grain structure, milling can substantially reduce vitamin content, while cooking methods can significantly impact vitamin retention and bioaccessibility. Pressure cooking has been reported to result in large vitamin losses, whereas minimal vitamin loss was observed following boiling. The fortification of cereal flour with vitamins B1, B2, B3, and B9, which are commonly deficient, has been recommended; and in addition, region-specific fortification using either synthetic or biological vitamins has been suggested. Biofortification is a relatively new concept and has been explored as a method to generate vitamin-rich crops. Once developed, biofortified crops can be utilized for several years. A recent cereal biofortification success story is the enrichment of maize with provitamin A carotenoids.

In-vitro Analysis of Trypsin and Alpha - Amylase Inhibitory Activities in Selected Legume Varieties in Sri Lanka

Aim: To quantify the Trypsin Inhibitory Activity (TIA) and Alpha - Amylase Inhibitory Activity (AIA) in legume varieties with effect of cooking. Study Design: Seeds of twelve legume varieties grown in Complete Randomized Block Design (CRBD) in experimental field conditions were used and data analysis was performed using one-way ANOVA at 95% confidence interval using MINITAB statistical software. Place and Duration of Study: Grain Legumes and Oil Crops Research and Development Centre (GLOCRDC), Angunakolapalessa and Industrial Technology Institute (ITI), Colombo, Sri Lanka between June 2019 and Dec 2019. Methods: Ethanolic (80%) extracts of raw and cooked grain legumes were used. In determining TIA, N-α-benzoyl-DL-arginine-p-nitroanilide hydrochloride (BAPA) is used as a synthetic substrate for trypsin enzyme and the rate of hydrolysis was measured by intensity of colour released by p-nitroaniline. AIA was carried out determining the maltose content which was released by hydrolysis of starch in the presence of amylase enzyme using reduction of 3, 5-dinitrosalicylic acid. Results: TIA in raw legumes ranged from 0.65±0.02 mg/g (ANK- Brown) to 1.52±0.01 mg/g (ANKCP1) while in cooked legumes ranged from -0.11±0.1 mg/g (ANK-Black) to 0.61±0.02 mg/g (MI 5). In pressure cooking (120oC, 10 min) considerable reduction in TIA of 53.74% (MI6) to 100% (ANK-Black, Bombay) was observed. A significant difference (p<0.05) in TIA among the varieties as well as among cooked form of varieties were observed (one- way ANOVA). Further a significant difference (p<0.05) in TIA was observed between cooked and raw form in each legume variety (Paired T-Test). AIA of cooked samples was ranged from - 11.61% (MI 6) - 23.05% (MISB1) and there was no significant difference (p<0.05) in AIA among the most of the legume varieties. Conclusion: A significant reduction of TIA among the legumes varieties was observed in the pressure cooking process while a significant activity of alpha- amylase was not seen in cooked legumes.

Statistical Optimization of Saccharification Process Using Amorphophallus Paeoniifolius Tubers into Fermentable Sugars for Bioethanol Production in Stirred Tank Batch Reactor (STBR)

Current technologies for the production of biofuels from various renewable feedstocks have considerably captured vast scientific attention due to the fact that they can be used as an alternative fuels. Bioethanol being one of the most interesting biofuels and due to its positive impact on the environment has been categorised significantly in terms of scientific and technological investments. The aim of this study was to investigate, tubers of Amorphophallus paeoniifolius biomass as a feedstock for bioethanol production. The composition analysis of A.paeoniifolius tubers revealed high carbohydrate content (78.30 ± 0.33%). The feedstock was subjected to physicochemical pretreatment by treating with dilute acid followed by pressure cooking. The pretreatment factors were optimized by CCD using RSM approach. The optimum condition was found to be 1.32%v/v of HCl, 5.83%w/v of Elephant Foot Yam Biomass and 66.84 min of pressure cooking time yielding 45.87 g/L of total sugar. The second order polynomial equation was generated for the saccharification of the biomass and validated with R2 0.89. The fermentation of pretreated biomass in the presence of Saccharomyces cerevisiae MTCC170 yielded 22.12 ± 0.62 g/L of bioethanol at 120 h utilising 92% of initial total sugar. The resultant ethanol yield and productivity was estimated to be 0.51 g/g and 0.30 g/L.h respectively. The Gompertz model equation was applied to experimental data using nonlinear regression with the least square method and the kinetic fermentation parameters such as maximum ethanol concentration (Pm), production rate (rpm) and lag phase (h) were estimated to be Pm =21.90 g/L, rpm =0.57 g/L.h and tL =8.22 h.