Plant-based flaxseed oil microcapsules fabricated from coacervation of gluten at oil droplet surface: Microstructure, oxidation stability, and oil digestion control

This study aimed to develop microcapsules with wheat gluten-coated oil droplets to enhance the oxidation stability and control the digestibility of flaxseed oil. The microcapsules were fabricated using a three-step procedure: (i) flaxseed oil was homogenized with an alkaline gluten solution to form oil-in-water emulsions containing small gluten-coated oil droplets (320-400 nm); (ii) the pH of these emulsions was then neutralized to facilitate the deposition of gluten around the oil droplets, thereby forming a thick layer; (iii) a flaxseed oil microcapsule powder was then prepared by spray drying. During the microcapsule formation, intermolecular interactions, including hydrophobic interactions and hydrogen bonds, were involved in the coacervation of gluten at the emulsion surface. The resultant microcapsules with a multiple-core structure had external diameters of 4-26 µm and encapsulation efficiencies of 90%-94%. The microencapsulated oil powders contained a relatively high flaxseed oil content (60%-80%). Among them, the sample with 60% oil content demonstrated the best stability in resisting oil droplet coalescence; thus, it exhibited a higher lipolysis rate and extent during simulated gastrointestinal digestion. A 30-day accelerated storage study showed that encapsulation of the flaxseed oil improved its resistance to oxidation. These findings suggest that the pH-deposition method can successfully produce microencapsulated polyunsaturated lipids using all plant-derived ingredients, which may facilitate their use in new plant-based foods through a green and sustainable approach.

Ultra-processed foods and the incidence of pre-diabetes and type 2 diabetes among Iranian adults: the Tehran lipid and glucose study

BACKGROUND

No study has investigated the association between ultra-processed food (UPF) and pre-diabetes development. Furthermore, prior investigations on the association between UPF and the risk of type 2 diabetes (T2D) were primarily conducted in Europe and America, and studies in other regions are lacking. We investigated the association between ultra-processed foods and the risk of pre-diabetes and T2D in a cohort of Iranians.

METHODS

This prospective study, with a sample size of 1954 for pre-diabetes and 2457 for T2D, was conducted among adults' participants (aged ≥ 18 years) from the Tehran Lipid and Glucose Study (TLGS). We defined UPF intake using NOVA calcification as a proportion of total energy, and calculated its average intake during the follow-ups. The hazard ratios (HR) and 95% confidence intervals (95% CI) for pre-diabetes/T2D across tertiles of total UPF and per 10% of its increment were examined using Cox proportional hazards models. We also investigated the possibility of non-linear association using a restricted cubic spline regression.

RESULTS

We identified 766 and 256 cases of pre-diabetes and T2D, respectively, during a median follow-up of 7 years for pre-diabetes and 8.6 years for T2D. In the multivariable adjusted model, a 10% increase in total UPF intake was associated with a 12% higher risk of pre-diabetes (HR = 1.12; 95% 1.02, 1.23). The incidence of pre-diabetes was also higher in those in tertile 3 than those in tertile 1 (HR = 1.28; 95% CI = 1.07, 1.52). Following additional adjustment for diet quality, the results remained unchanged. Spline regression demonstrated a J-shaped association between UPF and the risk of pre-diabetes; the risk of pre-diabetes did not increase until UPF consumption exceeded about 24% of total energy intake. Of the individual UPF, hydrogenated fat/mayonnaise/ margarine group was related to an increased risk of pre-diabetes. The total UPF and its individual items were not associated with T2D.

CONCLUSIONS

This study found a positive, non-linear relationship between total UPF and the risk of pre-diabetes in Iranian adults. Our data could not show any significant association between UPF and T2D risk.

Evaluation of high oleic sunflower oil oleogels with beeswax, beeswax-glyceryl monopalmitate, and beeswax-Span80 in cookie preparation

BACKGROUND

Shortening is used widely in cookie preparation to improve quality and texture. However, large amounts of saturated and trans fatty acids present in shortening have adverse effects on human health, and much effort has been made to reduce the use of shortening. The use of oleogels might be a suitable alternative. In this study, the oleogels of high oleic sunflower oil with beeswax (BW), BW-glyceryl monopalmitate (BW-GMP), and BW-Span80 (BW-S80) were prepared and their suitability to replace shortening in cookie preparation was evaluated.

RESULTS

The solid fat content of BW, BW-GMP, and BW-S80 oleogels was significantly lower than that of commercial shortening when the temperature was not higher than 35 °C. However, the oil-binding capacity of these oleogels was almost similar to that of shortening. The crystals in the shortening and oleogels were β' form mainly; however, the morphology of crystal aggregates in these oleogels was different from that of shortening. The textural and rheological properties of doughs prepared with the oleogels were similar, and clearly different from those of dough with commercial shortening. The breaking strengths of cookies made with oleogels were lower than that of cookies prepared with shortening. However, cookies containing BW-GMP and BW-S80 oleogels were similar in density and color to those prepared with shortening.

CONCLUSION

The textural properties and color of cookies with BW-GMP and BW-S80 oleogels were very similar to those of the cookies containing commercial shortening. The BW-GMP and BW-S80 oleogels could act as alternatives to shortening in the preparation of cookies. © 2023 Society of Chemical Industry.

Ultrasonic Treatment of Food Colloidal Systems Containing Oleogels: A Review

The use of oleogels as an alternative to solid fats to reduce the content of saturated and trans-isomeric fatty acids is a developing area of research. Studies devoted to the search for methods of obtaining oleogels with given properties are of current interest. Ultrasonic treatment as a method for modifying oleogel properties has been used to solve this problem. The number of publications on the study of the effect of ultrasonic treatment on oleogel properties is increasing. This review aimed to systematize and summarize existing data. It allowed us to identify the incompleteness of this data, assess the effect of ultrasonic treatment on oleogel properties, which depends on various factors, and identify the vector of this direction in the food industry. A more detailed description of the parameters of ultrasonic treatment is needed to compare the results between various publications. Ultrasonic treatment generally leads to a decrease in crystal size and an increase in oil-binding capacity, rheological properties, and hardness. The chemical composition of oleogels and the concentration of gelators, the amplitude and duration of sonication, the cooling rate, and the crystallization process stage at which the treatment occurs are shown to be the factors influencing the efficiency of the ultrasonic treatment.

Developing and optimizing low-saturated oleogel shortening based on ethyl cellulose and hydroxypropyl methyl cellulose biopolymers

Oleogels,gels in which the continuous liquid phase is oil, have been suggested as promising low-saturated alternatives to the conventional shortenings. In this study, we aimed to develop and optimize low saturated oleogel shortenings using ethylcellulose or ethylcellulose/hydroxypropyl methylcellulose biopolymers (as oleogelators), sunflower oil (as the base oil), and palm stearin (as the source of saturated fatty acids). Using the response surface-d-optimal method, oleogel formulations containing saturated fatty acids as low as 15.19 % could be developed. As compared to the commercial shortening samples, oleogel shortenings had much lower saturation levels (15.19-17.02 vs 47.87-58.65 %) but a comparable melting point, firmness, and rheological properties. However, oleogel samples had lower solid fat content and induction period of oxidation than commercial ones. Oleogel made using ethylcellulose/hydroxypropyl methylcellulose biopolymers contained lower saturation level, solid fat content, induction period of oxidation, and firmness but a higher melting point, as compared to that made using ethylcellulose.

Trans fatty acids in food: A review on dietary intake, health impact, regulations and alternatives

Trans fats are desired by the edible oil industry as they impart firmness, plasticity, and oxidative stability to oil. However, clinical trials have demonstrated the adverse effects of trans fats in food on human health and nutrition. Regulatory actions have been taken up by government and non-government bodies worldwide to eliminate the presence of trans fats in the food supply. The World Health Organization (WHO) has launched a "REPLACE" action plan to eliminate trans-fat from the global food industry by 2023. A few enabling technologies are developed to mitigate trans fats namely, trait-enhanced oils, modification in the hydrogenation process, interesterification, fractionation, blending, and oleogelation. Some of them have the drawback of replacing trans-fat with saturated fats. Interesterification and oleogelation are in-trend techniques with excellent potential in replacing trans fats without compromising the desired functionality and nutritional quality attributes. This review presents an overview of trans fatty acid for example, its dietary intake in food products, possible adverse health impact, regulations, and approaches to reduce the usage of trans fats for food application. PRACTICAL APPLICATION: The requirement for the replacement of trans fatty acids (TFAs) in food supply globally has challenged the food industry to find a novel substitute for trans fats without compromising the desired functionality and nutritional property. This review presents detailed background on trans fats, their health impacts and current trends of reformulation of oils and fats to mitigate their presence in food supply chains. Information compiled in this paper will help food scientists and technologists, chemists, food processors, and retailers as there is an urgent need to find novel technologies and substitutes to replace trans fats in processed foods.

Tutorial for the Characterization of Fatty Acid Methyl Esters by Gas Chromatography with Highly Polar Capillary Columns

The fatty acid composition of fats and oils is commonly determined by gas chromatography after preparing fatty acid methyl esters (FAME). Capillary columns coated with polyethylene glycol emerged as the preferred separation tool for the quantification of the polyunsaturated fatty acids contained primarily in marine oils. However, their selectivity is inadequate for measuring the trans fatty acids (TFA) contained in refined vegetable oils, dairy fats, and marine oils. Highly polar 100% poly(biscyanopropyl siloxane) capillary columns provide the necessary selectivity, but small differences in the phase polarity caused by column age, conditioning, or manufacturing variations affect the reproducibility of their separations of these complex samples. In this study, a simple procedure is described to compensate for small variations in column selectivity by adjusting the elution temperature. The balance between the dipole-induced dipole interactions and dispersive interactions was determined by measuring selectivity factors [SF(i)] corresponding to the elution of an unsaturated FAME such as 18:3n-3 relative to two saturated FAME such as 20:0 and 22:0. Knowing the SF(i) provided by the installed capillary column at a given elution temperature, and the SF(i) of the target separation, we propose a simple calculation to determine the necessary elution temperature adjustment to achieve (or restore) the desired separation. After determining the SF(i) which provides the optimal separation of TFA, the novel methodology was applied to the separation of refined vegetable oils, butter fats, and marine oils.