Vegetable oils as green solvents for carotenoid extraction from pumpkin (Cucurbita argyrosperma Huber) byproducts: Optimization of extraction parameters.

Pumpkin pulp is the main waste generated by pumpkin seed growers. This agro-industrial waste is a valuable source of bioactive compounds, especially carotenoids (ß-carotene, α-carotene, and lutein), which exhibit a broad spectrum of health-promoting effects. In this study, vegetable oils (canola, corn, and soybean oil) were used as green solvent alternatives to conventional organic solvents for carotenoid extraction from dried pumpkin pulp (DPP) waste. The highest carotenoid extraction yield (CEY) was obtained with canola oil, at a 1:10 DPP/oil ratio. Response surface methodology (RSM) was used to optimize the extraction process parameters (temperature, time, and stirring rate) through a Box-Behnken design (BBD) maximizing CEY in canola oil. The extraction temperature and stirring rate were found to have a significant linear and quadratic effect, respectively, on CEY. Optimum conditions were achieved at 21.8 min, 250 rpm, and 60°C. Under these optimized conditions, the estimated value for CEY was 378.1 µg ß-carotene equivalents/g of DPP, corresponding to 61.6% of the total carotenoid content present in the DPP. In contrast, the observed experimental value was 373.2 µg ß-carotene equivalents/g of DPP (61.2%). The experimental value was very close to the estimated value, which verifies the model's adequacy and fit. This study shows an alternative method to extract carotenoids from DPP with canola oil, obtaining an oil naturally enriched with carotenoids that could be used as a potential functional ingredient in the development of food, cosmetics, and medicinal products. PRACTICAL APPLICATION: Pumpkin by-products are a potential carotenoid source. Vegetable oil can be used as an alternative solvent for carotenoid extraction from pumpkin residues to obtain an enriched carotenoid oil that can be used to formulate food products.

Effect of pre-treatment on physicochemical and structural properties, and the bioaccessibility of ß-carotene in sweet potato flour.

The aim of this research was to evaluate the effect of microwave or steam pre-treatment of raw sweet potato on physicochemical and microstructural properties, and the bioaccessibility of ß-carotene in sweet potato flour. This is the first report on using the in vitro digestion model suitable for food, as proposed in a consensus paper, to assess the bioaccessibility of ß-carotene in sweet potato flour. The pre-treatments produced a rearrangement of the flour matrix (starch, protein and non-starch polysaccharides), which was greater by using microwaves (M6) conducting to a greater increase in the phase transition temperatures up to 4.14 °C, while the enthalpy presented the higher reduction (4.49 J/g), both parameters in respect to the control. The resistant starch fraction was not modified, with about 3% in all samples. Microwave (M6) and all the steam pre-treatments showed the higher bioaccessibility of ß-carotene. This flour can be used in the development of new products with high ß-carotene content.

Effect of different treatments on the preference of apple cubes dehydrated by a combined process.

The aim of this work was to determine the effect on consumer preference of dehydrated apple cubes caused by different modifications of a combined drying method. The combined process of convective-osmotic drying with pretreatment in solutions of CaCl(2) and citric acid was taken as the basic process, and was then modified to obtain six different treatments. The factors varied were the osmotic agent, the order of drying processes, and the addition of CaCl(2) to the osmotic solution. The drying kinetics of convective-osmotic treatment and the osmotic-convective process were studied. A sensory evaluation was conducted to determine the effect of these alterations in the drying process on the consumer preference for the product. The convective-osmotic treatment significantly reduced the time of processing. Water loss and solids gain were higher when fructose was used as the osmotic agent in the convective-osmotic process. According to the results of the preference test, only one of the modified processes showed significant preference compared with the basic process.