Edible insects as a novel source of lecithin: Extraction and lipid characterization of black soldier fly larvae and yellow mealworm.

Edible insects with high fat and phosphorus content are a potential novel source of lecithin, however, studies on their minor lipids are limited. In this study, lecithin was extracted from black soldier fly larvae and yellow mealworm. Herein, the effects of lecithin extraction method, matrix and ultrasound pretreatment were explored based on the fatty acid composition and phospholipid profile with soy lecithin as a reference. The use of a wet matrix and ultrasound pretreatment increased the extraction efficiency of total PLs from both insects. Insect lecithin contained a considerable amount of sphingomyelin compared to soy lecithin. In insect lecithin, a total of 47 glycerophospholipid and sphingomyelin molecular species, as well as four molecular species of fatty acyl esters of hydroxy fatty acid, were detected. This study is the first comprehensive investigation of insects as a new source of lecithin with applications in food, cosmetics and in the pharmaceutical industry.

Frying dough with yellow mealworm oil: Aroma profile and consumer perception at a central location test and at home.

Insect oil is a valuable fraction that is obtained from insect processing. The aim of this study is to evaluate the impact of yellow mealworm oil (YMW) oil (crude, deodorized, and blended with vegetable oil) on the sensory evaluation and aroma profile of fried dough. The sensory evaluation was performed in a sensory lab (central location test, CLT) and at home in order to examine how the evaluation environment or context impacts consumer perceptions. The strongest liking and preference were found for the donuts that were fried in 100% deodorized YMW oil and in YMW oil blended with vegetable oil. The evaluation environment did not affect overall liking scores but had an impact on sensory profiling, with more discriminating sensory terms observed for the test that was conducted at the sensory lab than for the test that was conducted at home. A distinctive profile of volatile organic compounds (VOCs) was found for every fried dough. The discrimination between VOCs and other frying oils that were observed is well in line with the sensory descriptors and the consumer test results. Acetic acid, acetic acid ethenyl ester, and tetrahydro-6-propyl-2H-Pyran-2-one were present in the doughs that were fried in crude YMW oil and in its blend with vegetable oil. They were absent from deodorized YMW oil and from its blend with vegetable oil. This study shows that, as far as fried donuts are concerned, deodorized YMW oil is an alternative to a vegetable oil-the two lead to similar sensorial experiences and preferences. PRACTICAL APPLICATION: Yellow mealworm oil (YMW) oil is a co-product of insect protein that can be valorized in the food industry. In the present study, it is demonstrated that the deodorization of YMW oil produces positive sensorial experiences and increases consumer acceptance of insect-based food. Furthermore, findings indicate that consumer testing at home yields similar acceptance and preference ratings suggesting that this type of testing may be an alternative means of collecting reliable consumer data.

Replacing vegetable oil by insect oil in food products: Effect of deodorization on the sensory evaluation.

Introducing processed insects in food products is seen as a way to lower the barrier for insect consumption by Western consumers. Prior research indicated that crude insect lipids could partially replace butter in bakery products without influencing consumer's perception, but a complete substitution remained a challenge due to the presence of off-flavors. This study proposes oil deodorization as a means to reduce insect oil off-flavors and increase insect oil replacement in food products. We compared the effect of deodorization of yellow mealworm (YMW, Tenebrio molitor) oil on the partial and total replacement of vegetable oil in crackers and hummus. In total 253 participants joined the study (127 crackers study, 126 hummus study). Each participant evaluated 5 samples, 100% vegetable oil, 100% crude YMW oil, 100% deodorized YMW oil, 50% vegetable & 50% crude YMW oil and 50% vegetable & 50% deodorized YMW oil. Results showed that deodorized YMW oil could replace vegetable oil in both products without changing the overall food experience, liking and visual appearance in the products. In contrast, using crude YMW oil impacted the overall liking and certain sensory attributes, mostly related to flavor. Moreover, the use of deodorized YMW eliminated visual differences amongst the products. When YMW oil was used in a dispersion-like food, such as hummus, a less firm, more spreadable and less sticky hummus was obtained. Crude YMW oil also reduced hardness in low-moisture solid foods, such as crackers but further studies are necessary to fully understand this effect.

Lipidome of cricket species used as food.

The variation in lipidome of house cricket, banded cricket, Jamaican field cricket and two-spotted cricket was studied using high-throughput screening techniques for fingerprinting (MALDI TOF MS, GC-MS and LC MS-MS) and well-stablished chromatographic techniques for quantification (HPLC-ELSD, GC- FID). Although the four cricket species were reared in identical conditions, two-spotted & banded crickets had a lipid content 1.5 fold higher than house cricket. The lipids were high in UFA (>63%) and unsaturated TAG (>98%) making them liquid at room temperature, thus an oil. Cholesterol and several phytosterols were profiled finding high cholesterol concentration which is a point of concern. Eight phospholipid types (211 species) were identified with no major differences among cricket species. Using high-throughput screening techniques we demonstrate the complexity of cricket lipidome. Information on the lipidome of these crickets with high commercial value is important to estimate its nutritional value and their potential food applications.

Modulating the crystallization of phytosterols with monoglycerides in the binary mixture systems: mixing behavior and eutectic formation.

Phytosterols (PSs) are insoluble in water and poorly soluble in oil, which hampers their potential as cholesterol level regulator in human. To mitigate this problem, monoglycerides (MGs) were used to modulates the crystallization behavior of PSs. Therefore, the understanding on mixing behavior provides the insight into different aspects of crystallization and the resultant effects. The effects on thermal, morphology, diffraction, and spectroscopy behavior were investigated for binary mixtures of 11 different ratios (100:0 to 0:100 MGs:PSs). The phase behavior of binary mixtures of commercial MGs and PSs exhibited complexity with the formation of eutectic mixtures at 90:10 and 80:20 (MGs:PSs) combinations. These combinations revealed a single melting profile and reduced melting enthalpy, though after a month of storage at 5 °C. Conversely, two separate melting regions were observed in others. Furthermore, powder X-ray diffraction (PXRD) analysis of selected combinations revealed a change in crystalline forms with changes in the peaks located between 18-19° (2θ) and 25-26° (2θ). Accordingly, Raman spectroscopy results revealed changes in intensities and peak shape. Therefore, the change in crystalline forms or behavior correlated well to the change in thermal properties. Overall, the characterizations revealed the formation of eutectic mixtures between MGs and PSs at 90:10 and 80:20 (MGs:PSs) in which MGs modified the crystallization of PSs and changed the crystal forms thus, thermal behaviors. This study provides new insight into the mixing behavior of MGs and PSs which supports other research. Therefore, the results of this study are beneficial for the improvement of formulation of phytosterols in food and pharmaceutical products. Nonetheless, this study reveals a simple technique to alter crystal forms of phytosterols through simple complexation with monoglycerides.

The DGAT1 K232A polymorphism and feeding modify milk fat triacylglycerol composition.

In the present study, we aimed to investigate the changes in triacylglycerol (TAG) composition as affected by alterations in the cows' diet due to seasonal variations and genetic factors. For this study, 50 milk fat samples in winter and 50 in summer were used from 25 cows with the DGAT1 KK genotype and 25 cows with the DGAT1 AA genotype. The samples were analyzed for milk fat content (%), fat composition, and TAG composition. We found that the content of TAG species CN54 was higher and that of CN34 and CN36 lower in summer than in winter. This seasonal variation in TAG profile was related to seasonal changes in the fatty acids C14:0, C16:0, C18:0, C18:1 cis-9, total unsaturated fatty acids, and total long-chain fatty acids, most likely resulting from dietary differences between seasons. Furthermore, we quantified the effect of DGAT1 K232A polymorphism on TAG profile and detected a significant effect on TAG species CN36, with higher values for the DGAT1 KK genotype. When adjusting for differences in fat content, we found no significant effects of the DGAT1 K232A polymorphism on TAG profile. We detected a significant interaction between DGAT1 K232A polymorphism and season for TAG species CN42 and CN52; in summer, the KK genotype was associated with higher levels for CN42 than the AA genotype, whereas in winter, the difference between the genotypes was small. For CN52, in summer the AA genotype was associated with higher levels than the KK genotype. In winter, the difference between the genotypes was also small. We show that, regardless of preference for DGAT1 genotype (AA or KK) and depending on the availability of FA according to season, UFA (C18:1 cis-9), short-chain FA (C6:0 and C10:0), and medium-chain FA might be esterified on the glycerol backbone of the TAG, keeping the structure characteristics of each TAG species. To our knowledge, this is the first report on the interaction effect of DGAT1 K232A polymorphism and season on the TAG composition in milk fat.

Influence of cooling rate on partial coalescence in natural dairy cream.

The presence of a fat crystal network throughout the fat droplets of an oil-in-water emulsion is a requisite for partial coalescence. The characteristics of this fat crystal network determine greatly the kinetics of partial coalescence. In this study the fat crystal network was manipulated by altering the cooling rate applied to natural cream. The kinetics of partial coalescence under constant shear and at constant temperature were studied by combining rotational viscosity analysis with light microscopy and laser scattering. It was shown that slow cooling of the emulsion decelerates partial coalescence and favors the formation of loosely-packed aggregates. On the other hand, fast cooling favors a high partial coalescence rate and the formation of dense aggregates. Fat crystallization properties were analyzed using small deformation rheology, differential scanning calorimetry and cryo-scanning electron microscopy. The difference in organization of the fat crystals obtained for both cooling rates contributed significantly to the mechanistic understanding of partial coalescence as influenced by the cooling rate.

Formation of ß Polymorphs in Milk Fats with Large Differences in Triacylglycerol Profiles.

In this study, we characterized the polymorphism of milk fat (MF) with various TAG compositions during isothermal crystallization at 20 °C. TAG composition of MF from seven individual cows was determined using GC-FID and MALDI-TOF MS, and MF polymorphism was studied using X-ray diffraction. Results showed that TAG profile determines the polymorphic behavior of MF. Saturated TAG with carbon numbers 34-38 promoted the formation of α polymorphs, whereas unsaturated TAG with 52-54 promoted the formation of the ß polymorphs. Furthermore, MFs with unsaturated fatty acid profiles were increased in unsaturated TAG with 52-54 carbons. The presence of MF crystals in the ß polymorph has been controversial over the years as most authors mainly find MF crystals in the α and ß' form. In our work, we showed that the ß polymorph is formed in MF on the basis of its TAG composition.