Lipase-Mediated Interesterification of Oils for Improving Rheological, Heat Transfer Properties and Stability During Deep-Fat Frying

Enzymatic Interesterification of Coconut and Hemp Oil Mixtures to Obtain Modified Structured Lipids

The interesterification process allows structured lipids (SLs) to be obtained with a modified triacylglycerol (TAG) structure, in which the unfavorable saturated fatty acids (SFAs) are replaced with nutritionally significant fatty acids (FAs) such as monounsaturated (MUFAs) and polyunsaturated (PUFAs). Oxidative stability is crucial for the quality of SLs. This study aimed to characterize and evaluate the FA profile and oxidative stability of SLs synthesized by the enzymatic interesterification of hemp seed oil (HO) and coconut oil (CO) blends. Blends were prepared in three ratios (75% HO:25% CO, 50% HO:50% CO, and 25% HO:75% CO) and interesterified using sn-1,3 regiospecific lipase for 2 or 6 h. FA composition, the FA distribution of TAGs, acid value (AV), peroxide value (PV), and oxidation time were analyzed and compared to non-interesterified blends. Results showed no significant difference in the SFA:MUFA ratios between interesterified and non-interesterified blends with the same proportions. Lauric acid predominantly occupied the sn-2 position in all blends. Interesterified blends had higher AVs, exceeding codex standards, while PVs remained within the acceptable limits. Blends with 75% HO had lower oxidation times compared to those with 75% CO, with no significant difference between interesterified and non-interesterified blends. In the interesterification process of the studied blends, new TAGs with a modified structure were created, which may affect their physical and nutritional properties. This process also had a significant effect on the AV and PV levels, but not on the oxidation time of the modified blends. Therefore, it is necessary to remove free FAs after the enzymatic process to produce SLs characterized by improved hydrolytic stability. This will lead to better technological properties compared to the original oils. Further research is also necessary to enhance the oxidation stability of SLs obtained from blends of CO and HO to improve their storage stability.

Recent advances in enzymatic modification techniques to improve the quality of flour-based fried foods

Flour-based fried foods are among the most commonly consumed foods worldwide. However, the sensory attributes and nutritional value of fried foods are inconsistent and unstable. Therefore, the creation of fried foods with desirable sensory attributes and good nutritional value remains a major challenge for the development of the fried food industry. The quality of flour-based fried foods can sometimes be improved by physical methods and the addition of chemical modifiers. However, enzyme modification is widely accepted by consumers due to its unique advantages of specificity, mild processing conditions and high safety. Therefore, it is important to elucidate the effects of enzyme treatments on the sensory attributes (color, flavor and texture), oil absorption and digestibility of flour-based fried foods. This paper reviews recent research progress in utilizing enzyme modification to improve the quality of flour-based fried foods. This paper begins with the effects of common enzymes on the physicochemical properties (rheological property, retrogradation property and specific volume) of dough. Based on the analysis of the mechanism of formation of sensory attributes and nutritional properties, it focuses on the application of amylase, protease, transglutaminase, and lipase in the regulation of sensory attributes and nutritional properties of flour-based fried foods.

Enhancement of Oxidative Stability of Perilla Seed Oil by Blending It with Other Vegetable Oils

Perilla seed oil is mainly composed of omega-3 fatty acid (α-linolenic acid, ALA). Despite being nutritionally favorable and rich in unsaturated fatty acids, its low oxidative stability limits its application in food. Thus, the present study aimed to formulate a stable oil blend using perilla seed oil with selected vegetable oil of higher stability characteristics and balance the ratio of the fatty acids. Hence, improving the nutritional and functional value of the blended oil. Perilla seed oil was blended with different edible oil (palm olein, coconut oil, and groundnut oil) in ratios of 20:80 and 30:70. All the blended oils were studied for their fatty acid composition, physicochemical properties, oxidative stability, and nutritional quality index. It was found that perilla seed oil blended with saturated oil like palm olein had improved physicochemical properties and oxidative stability (0.5 h to 6.5 h). The fatty acids ratio of perilla and palm olein blends was close to the recommended value given by the World health organization (WHO). The nutritional quality indices (atherogenic index, the thrombogenic index, and hypocholesterolemic: hypercholesterolemic ratio) of blended oil were also improved compared to the individual oils.

Enzymatic interesterification effect on the physicochemical and technological properties of cupuassu seed fat and inaja pulp oil blends

The objective of this work was to evaluate the effect of enzymatic interesterification process in blends with different proportions (w:w) of cupuassu fat and inaja oil (80:20, 70:30, 60:40, 50:50 and 40:60). The interesterification reaction was carried out at 65 °C, agitation at 150 rpm, and enzyme concentration of 5% (w/w), for 6 h. Acidity index, melting point, consistency and solid fat content of the blends were characterized before and after the interesterification process. Fatty acid content was characterized in cupuassu fat and inaja oil and, nutritional quality indexes of atherogenicity (AI) and thrombogenicity (TI) were calculated. Enzymatic interesterification promoted a decrease in acidity (<0.6%) and changes in the blends' properties, making them suitable for food product preparation. All esterified blends (cupuassu seed fat:inaja pulp oil) presented suitable consistency properties, plasticity and spreadability to be used for the preparation of functional, table and soft table types of margarine and used in food preparation such as special fats.

Status of the bioactive phytoceuticals during deep-fat frying of snack food using nutra-coconut oil

The present study was carried out to study the physico-chemical changes that take place in both product and oil during the deep fat frying of a traditional savoury snack 'kodubale', at 120-160 °C for 120-600 s using coconut oil (CO) and nutra-coconut oil (NCO). Further, kinetic studies on moisture loss, oil uptake, color and degradation of β-carotene, total polyphenol content and antioxidant activity for kodubale was carried out during frying as a function of temperature and time. The study showed that the kinetic coefficients for above parameters increased with temperature and time and the data obtained were well fitted with first order kinetic model. The results also revealed that NCO fried product retained major phenolic acids due to the presence of antioxidants in the NCO which was enriched with flaxseed oil concentrate. The fatty acids profile of oil extracted from products obtained by frying using NCO was characterized with higher ω-3 and ω-6 fatty acids content as compared to same obtained using CO. However, the breaking strength and sensory characteristics of CO and NCO fried kodubale was found to have no significant difference (p < 0.05).