Physicochemical and rheological characterization of “dulce de leche,” a milk‐based sauce especially popular in South America, was carried out on different types of commercial products (traditional, confectionery, reduced calories or reduced fat). Proximal composition, solid content, water activity, pH and color (Minolta Co., Ramsey, NJ) were evaluated. A controlled stress rheometer (Haake RS600; ThermoGap, Karlsruhe, Germany) was used to perform flow curves, dynamic oscillatory test in the linear viscoelastic range and creep‐recovery experiments. Although in all samples, η decreased with increasing γ′, corresponding to shear‐thinning behavior, clear differences were found in the rheological characteristics of different types of products. Experimental dynamic data were successfully modeled using the Baumgärtel–Schausberger–Winter equation to predict the mechanical relaxation spectrum. Satisfactory prediction of other mechanical properties was validated using creep experiments. PRACTICAL APPLICATIONS In spite of the differences in composition and rheological behavior of the several types of “dulce de leche” studied, it was possible to analyze the rheological characteristics of all systems and model the obtained results using the broadened Baumgärtel–Schausberger–Winter (BSW) model as a representation of the relaxation spectra to convert dynamic data into time domain. The parameters of the BSW model were used to explain structural characteristics of the systems; thus, the overall microstructural pattern of “dulce de leche” might be similar, and the differences observed would be mainly explained by the level of interactions among macromolecular components. Using the discrete spectrum obtained from the BSW model, it was possible to calculate other viscoelastic properties of interest; thus, the proposed methodology is a useful tool, especially for establishing a rheological data bank and analyzing viscoelastic experiments of this type of product.

BACKGROUND: Numerous non-meat ingredients, such as hydrocolloids, starches, and fibers, have been studied to improve texture characteristics and increase the ability to bind water in low-fat meat products. In this sense, pulses flours (lentil, chickpea, pea, and bean) were studied at two levels and various water:flour ratios to replace 10-44% pork meat in low-fat burgers and determine the effect on their sensory and technological properties (cooking yield, expressible liquid, diameter reduction, and color and texture profile).RESULTS: All pork-meat burgers that included pulse flour showed higher cooking yields, lower diameter reductions, and expressible liquids than all-meat burgers, which displayed better oil and water retention. Higher water additions resulted in burgers with less hardness. Burgers with 80 g kg −1 lentil flour in all water/flour ratios presented the lowest total color difference (ΔE) compared with the commercial control. Burgers with the higher level of all pulse flour tested and medium water levels showed acceptable sensory scores. CONCLUSIONS: Partial pork meat replacement by different legume flour (lentil, chickpea, pea, and bean), at levels of 80 and 150 g kg −1 and water/flour ratios of 1250, 1600, and 2000 g kg −1 resulted in low-fat burgers with adequate physicochemical characteristics. Moreover, the sensorial evaluation of the formulations with the maximum flour addition and intermediate water/flour ratio showed that they had good sensorial acceptability with no effect of flour type.

No abstract

“Dulce de leche” (DL) is a rich, creamy, caramel‐like milk‐based sauce or spread, prepared by concentrating whole milk with sucrose, reaching a lipid content of about 6% w/w. A DL‐like product with pre‐emulsified pecan oil as fat source was developed. Nonfat milk, xanthan gum, sugars, pecan oil, and natural tocopherols were included in the formulation prepared in a pilot‐plant scale and stored at room temperature. Pecan oil‐DL showed physicochemical and rheological characteristics similar to those of commercial DL containing ∼6% milk fat. A slight increase in viscosity was observed after 2 months of storage, remaining almost constant thereafter. Crystal formation was not observed and microbial counts were low. Slight lipid oxidation was experienced after 138 days. DL fatty acid (FA) profile showed high content of unsaturated FA (UFA, 89–90% w/w), mainly oleic and linoleic acids, effectively protected by both tocopherols and antioxidant compounds. Pecan oil‐DL presented good sensorial characteristics (above 7 points on a 10 point‐hedonic scale), with 82.6% less saturated FA and 200% more UFA than a traditional milk fat‐product, being an alternative product with lipid profile enriched in unsaturated fatty acids. Practical applications: The “dulce de leche” (DL) jam‐like developed could be considered an alternative to the traditional DL, with better nutritional value considering its lipid composition. It has a fatty acid (FA) balance in favor of unsaturated FA as well as absence of cholesterol in the formulation because it is a product elaborated with nonfat milk. DL formulated with pecan oil showed physicochemical, rheological, and sensory characteristics similar to commercial products that contain about ∼6% milk fat. It showed good stability during storage at room temperature, with no lactose crystal formation, and only slight lipid oxidation. The product was successfully developed in the laboratory and also produced in a pilot plant scale, thus, it is feasible to produce it at an industrial scale. A DL‐like product with pre‐emulsified pecan oil as fat source was developed. Pecan oil‐DL showed physicochemical and rheological characteristics similar to those of commercial DL containing ∼6% milk fat. DL fatty acid (FA) profile showed high content of unsaturated FA (UFA, 89–90% w/w), mainly oleic and linoleic acids, effectively protected by both tocopherols and antioxidant compounds. Pecan oil‐DL presented good sensorial characteristics, with 82.6% less saturated FA and 200% more UFA than a traditional milk fat‐product, being an alternative product with lipid profile enriched in unsaturated fatty acids.

No abstract

For the development of gelatinized dairy products that include emulsified pecan oil as an unsaturated fatty acid source the incorporation of hydrocolloids becomes necessary and their properties must be carefully selected. This work aimed to study gelatinized candies made with 0% milk fat dulce de leche with pre-emulsified pecan nut oil using combinations of gelatin (4.67 to 7 g/100 g) and high methoxyl pectin (1.33 to 2 g/100 g) as gelling agents. The effect of different drying methods (vacuum-oven at 35 °C for 24 h and freeze-drying) was evaluated. Control samples without drying were also studied. Dehydration conditions significantly (p < 0.05) affected aw, texture (hardness, cohesiveness, adhesiveness, gumminess, springiness, and resilience) and color parameters (L*, a*, b*) of products, being higher than the effect of the gelling agent. Formulations were selected based on texture and aw criteria and sensory evaluated by appearance, color, texture, taste, and overall acceptability. Two formulations (one with 7% gelatin and 1.33% high methoxyl pectin content, and the other with 2% high methoxyl pectin and 4.67% gelatin content), both with low moisture content and vacuum-dried, exhibited good acceptability. These pecan oil-dulce de leche gummy candies would represent a healthier candy version, low in saturated fatty acids, and source of oleic acid.

No abstract

No abstract