Erasmo Herman-Lara

Effect of Osmotic Dehydration on Air-Drying Characteristics of Chayote

In this study the effect of osmotic dehydration (OD) on the air-drying kinetics of chayote (Sechium edule (Jacq.) Swartz) fruits was investigated. Fresh and osmotically dehydrated chayote parallelepipeds (1 × 1 × 2 and 4 × 4 × 2 cm) were subjected to convective drying at air temperatures of 50 and 60°C, with air velocities of 1.5 and 2.5 m/s. The OD pretreatments were performed in 10 and 25% NaCl solutions (w/w) at 25°C during 3 h using a solution-to-fruit mass ratio of 4:1. The use of higher air velocities notably accelerated drying rates as manifested through significantly higher drying rate constants estimated with Pages model, whereas no effect of temperature was observed. A previously reported analytical solution that considers both product shrinkage and variable diffusivity was generalized to describe the drying kinetics of food products with parallelepiped geometry. Selected drying experiments were then fitted to this solution using six different sets of model assumptions. Results indicated that product shrinkage is the main factor to be considered in order to estimate reliable values for diffusion coefficients. The OD pretreatments produced a significant reduction of the initial moisture content of chayote slabs before drying, thus allowing shorter drying time, which may lead to reduced energy consumption.

Effect of oil extraction assisted by ultrasound on the physicochemical properties and fatty acid profile of pumpkin seed oil (Cucurbita pepo).

The effects of amplitude and time of ultrasound-assisted extraction on the physicochemical properties and the fatty acid profile of pumpkin seed oil (Cucurbita pepo) were evaluated. Ultrasound time (5-30 min) and the response variables amplitude (25-100%), extraction yield, efficiency, oxidative stability in terms of the free fatty acids (FFA) of the plant design comprising two independent experiments variables, peroxide (PV), p-anisidine (AV), totox value (TV) and the fatty acid profile were evaluated. The results were analyzed by multiple linear regression. The time and amplitude showed significant differences (P<0.05) for all variables. The highest yield of extraction was achieved at 5 min and amplitude of 62.5% (62%). However, the optimal ultrasound-assisted extraction conditions were as follows: ultrasound time of 26.34 min and amplitude of 89.02%. All extracts showed low FFA (2.75-4.93% oleic acid), PV (1.67-4.68 meq/kg), AV (1.94-3.69) and TV (6.25-12.55) values. The main fatty acids in all the extracts were oleic and linoleic acid. Therefore, ultrasound-assisted oil extraction had increased performance and reduced extraction time without affecting the oil quality.

Evaluation of physical and chemical properties of carrots dried by Refractance Window drying

ABSTRACT The Refractance Window™ (RW) technique was used to dry carrot slices (3 cm diameter; 0.2 and 0.4 cm thickness) at 74 and 94°C. Moisture loss, texture, color, total polyphenol content (TPC), and antioxidant activity (AA) were evaluated as response variables and were compared with the values of a control (fresh carrot) and the slices dried via convective drying (C) at the same temperatures. The RW method produced a reduction of drying time of 26–51% (p < 0.05) when compared to convective drying. The color, TPC, and AA values for the RW treatment did not differ (p > 0.05) compared with the control. The texture values showed a difference with respect to the control for the two drying methods used. However, between the two drying methods there was no difference in the texture (p > 0.05). The results suggest that the RW technology can be used to develop products with better functional properties compared with those obtained via conventional air-drying methods.

Impact of micronized starfruit (Averrhoa carambola L.) fiber concentrate on lipid metabolism in mice

Abstract The objective of this study was to evaluate the effect of micronized insoluble fiber from starfruit bagasse as an ingredient of a functional food (FF) or as micronized insoluble fiber-rich fraction (IFRF) and its effects in vivo on lipids metabolism in a murine model. Experimental animals were divided in four isoproteic (15.8%) treatments differing on the fiber and cholesterol level used. The micronized IFRF particle size ranged from 37.5 to 149 μm. Treatments with added IFRF and those including the FF lowered serum triacylglycerols, total cholesterol (TC), high-density lipoproteins (HDL), and low-density lipoproteins (LDL) concentrations (IFRF: 14.2, 25.4, 55.06, and 12.18%, respectively; FF: 30.18, 39.47, 35.11, and 43.18%, respectively). IFRF produced the overall highest serum hypolipidemic effect and prevented the development of non-alcoholic fatty liver. Both the IFRF and the FF exhibited hypolipidemic effects that suggest a potential role of starfruit insoluble fiber as a component of FFs aimed against cardiovascular diseases.

Effect of some variables on oil extraction yield from Mexican pumpkin seeds

The effect of particle size (0.59 and 1.19 mm), meal to solvent ratio (1:5, 1:10, 1:15, and 1:20 w/v) and contact time (0, 1, 2, and 5 h) on oil extraction yield and efficiency from pumpkin (Cucurbita pepo) seeds using n-hexane were evaluated. Fatty acids profile was determined for the extracted oil. Results were analyzed by response surface methodology. Particle size, meal to solvent ratio and contact time, affected (p < 0.05) extraction yield. The yield (422 g/kg) and efficiency (860 g/kg) were highest at 0 h contact time, 0.59 mm particle size and a 1:20 (w/v) pumpkin seed meal:solvent ratio. Pumpkin seed oil contained (755 g/kg) unsaturated fatty acids and an elevated content of linoleic (431 g/kg) and oleic acids (324 g/kg). It is therefore classified as a high linoleic-oleic acids oil, making it a promising substitute for cotton, corn, sesame, sunflower, or soybean oils in our Mexican diet.

Conjugated linoleic acid content in selected Mexican beef and dairy products

The purpose of this study was to assess the conjugated linoleic acid (CLA) content of some commercial beef cuts and dairy products. Levels of CLA ranged between 3.75 and 20.45 mg/g fat, corresponding to 2% milk and cooked ground beef. On the basis of serving size, CLA content ranged between 12.87 and 93.62 mg/portion, corresponding to cream cheese (portion of 15 g) and cooked ground beef (portion of 100 g). There was no direct relationship between CLA content and the amount of fat provided per serving size in dairy foods. This study showed the presence of significant amounts of natural CLA in beef and dairy fats in the foods analyzed.

Sensory profiles of artisan goat cheeses as influenced by the cultural context and the type of panel

Summary The research was performed to evaluate influence of the cultural context and the type of panel on sensory profiles of artisan goat cheeses. Two types of sensory panels from the goat cheese-making region (experienced/trained artisan cheese producers vs. goat cheese consumers) and two types of sensory panels from a city area (trained descriptive panellists vs. cheese consumers) were formed. The sensory profiles generated with QDA® and Flash Profile techniques were compared using the hierarchical multiple factor analysis at two levels: type of panel and geographical area. This study demonstrated that sensory panels from the goat cheese-making region used lesser attributes for characterising cheeses. Some discrepancies in sensory profiles were found between the two consumer panels. The two experienced/trained panels were more discriminative and their sensory profiles were similar. Recruiting artisan goat cheese producers for sensory profiling of their own products is a reasonable alternative when training is appropriately conducted.

Relevant Aspects of the Development of Extruded High-Protein Snacks: An Alternative to Reduce Global Undernourishment

Abstract There are currently a number of health problems worldwide, especially in underdeveloped and developing countries, which are caused by factors such as traditions, customs, and inadequate food availability. Protein malnutrition is one of these problems and mainly affects children who consume large quantities of snacks that are high in fats and carbohydrates. For this reason, alternative feeding practices that contribute to good nutrition are needed. The technology that is most commonly used for the production of snacks is the extrusion process. This is a mechanical process that induces thermal and mechanical energy to process food at a high pressure and temperature for a short time. Most of these snacks are made with cornstarch, wheat, rice, oats, and potatoes, but are low in nutritional value (e.g., protein, fiber, and vitamins). The wide acceptance of such products has led researchers to develop various snacks that are rich in proteins, exploring the use of unconventional raw materials such as milk proteins, legume seeds, and vegetable flour. Therefore this review explores the most important parameters in the development of extruded snacks to deliver protein sources to address the global issue of protein malnutrition.

Comparison of performance and quantitative descriptive analysis sensory profiling and its relationship to consumer liking between the artisanal cheese producers panel and the descriptive trained panel

The aim of this research was to compare the performance and sensory profiling of a panel of artisanal cheese producers against a trained panel and their relationship to consumer liking (external preference mapping). Performance was analyzed statistically at an individual level using the Fishers test (F) for discrimination, the mean square error for repeatability, and Manhattan plots for visualizing the intra-panel homogeneity. At group level, performance was evaluated using ANOVA. External preference mapping technique was applied to determine the efficiency of each sensory profile. Results showed that the producers panel was discriminant and repetitive with a performance similar to that of the trained panel. Manhattan plots showed that the performance of artisanal cheese producers was more homogeneous than trained panelists. The correlation between sensory profiles (Rv = 0.95) demonstrated similarities in the generation and use of sensory profiles. The external preference maps generated individually with the profiles of each panel were also similar. Recruiting individuals familiar with the production of artisanal cheeses as panelists is a viable strategy for sensory characterization of artisanal cheeses within their context of origin because their results were similar to those from the trained panel and can be correlated with consumer liking data.

Effect of osmotic dehydration on the physical and chemical properties of Mexican ginger (Zingiber officinale var. Grand Cayman)

The aim of this study was to evaluate the effect of osmotic dehydration of ginger on the properties of color, total polyphenol content (TPC) and antioxidant capacity (AC). Fresh samples were pretreated with scalding (100°C/1.0 minute). Water loss (WL) and solid gain (SG) kinetics were performed using three sucrose concentrations: 35%, 50% and 65% at three temperatures: 40°C, 55°C and 70°C. WL and SG simulated kinetics by Diffusion model for cubes averaged a R2 of 0.95. The diffusivities for water and solid by Fick’s Law obtained maximum values of 6.81 × 10−7 and 2.65 × 10−7 m2/s, respectively. WL results were obtained up to 60.83% and SG 32.24%. Ginger treatments without blanching (GWB) at 40°C with 35% and 50% sucrose, respectively, showed a similar fresh ginger color. The GWB treatments showed the higher TPC using 50% sucrose at 40°C (753 μg GAE/mL) and AC (341.96 mg AAE/mL).