Dulce de leche‐like product enriched with emulsified pecan oil: Assessment of physicochemical characteristics, quality attributes, and shelf‐life

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.

Lipolysis and Oxidation in Ultra‐High Temperature Milk Depend on Sampling Month, Storage Duration, and Temperature

“…As expected, smaller changes were found at low temperatures (Figure j–l). This result is consistent with other studies showing a higher degree of lipid oxidation in milk products stored at higher temperatures (Mahmoodani, Perera, Abernethy, Fedrizzi, & Chen, ; Ranalli et al., ). Refrigerated storage temperature (4 °C) prevents the formation of TBARS in UHT milk compared with storage at room temperature (20 °C) or higher temperatures (30 and 37 °C).…”

“…The similar minor increase in TBARS concentrations (Figure a) in UHT milk from all sampling months (May, July, and November) during the first 3 months of storage could have been caused by a slow formation of free radicals (Barden & Decker, ). The continuous increase in TBARS concentration in milk from all three sampling months stored for 3 to 12 months, as also found in other studies (Citta et al., ; Ranalli, Andrés, & Califano, ), is related to decomposition of primary oxidative products and accumulation of secondary products. The low formation of FFA during storage of summer milk (July) compared with other milk (May and November) may be due to: (1) the diet (fresh grass) fed to cows resulting in a relatively higher proportion of PL and lower proportion of TAG (Lu et al., ) and (2) possibly higher amounts of carotenoids and other stabilizing molecules.…”

Effect of Different Storage Conditions on Analytical and Sensory Quality of Thermally Processed, Milk‐Based Germinated Foxtail Millet Porridge

“…This behavior of the Herschel‐Bulkley's equation parameters, were also studied by Ranalli et al. (), who quoted similar results for a milk product, Dulce de leche ‐like product enriched with emulsified pecan oil. Higher values of σ 0 and K for retort processed foxtail millet porridge samples as compared to the UHT treated foxtail millet porridge samples could be due to intense thermal treatment of the porridge in case of retort processing.…”

“…This age thickening could be due to structural rearrangements caused due to thermal process induced changes in casein micelles, proteins, and fat globules. Storage of thermally processed porridge also causes modifications like aggregation, denaturation, polymerization, and so on in the continuous phase by increasing the volume of the dispersed components (Ranalli, Andrés, & Califano, ). These results were in agreement with the findings of Abdulghani, Prakash, Ali, and Deeth () for UHT milk fortified with iron, magnesium and zinc.…”

“…() for chhana kheer and Ranalli et al. () for Dulce de leche ‐like product enriched with emulsified pecan oil.…”