Bioactive compounds, besides presenting basic nutritional functions, provide metabolic and physiological health benefits when consumed as part of the usual diet. Therefore, there is a growing interest in vegetable oils of special composition, such as the ones extracted from fruit seeds. The seeds of Cucurbita sp are shown to be promising sources of oils, and especially the Cucurbita moschata and maxima species have not yet been fully elucidated. For this reason, it becomes important to investigate the chemical composition and lipid fractions of these seeds, aiming to use them in food.

Emerald is a global publisher linking research and practice to the benefit of society. The company manages a portfolio of more than 290 journals and over 2,350 books and book series volumes, as well as providing an extensive range of online products and additional customer resources and services. Emerald is both COUNTER 4 and TRANSFER compliant. The organization is a partner of the Committee on Publication Ethics (COPE) and also works with Portico and the LOCKSS initiative for digital archive preservation.

This study aimed to evaluate the oils of soybean (S), papaya (Pa) and melon (Me) seeds and compounds oils SPa (80:20 w/w); SMe (80:20 w/w); and SPaMe (60:20:20 w/w/w) subjected to thermoxidation. Compound oils showed lower percentages of free fatty acids in relation to others, after 20 h. With the heating process, there was an increase in the quantity of saturated and monounsaturated acids. The quantity of carotenoids decreased, except in papaya seed oil that presented significant amount of carotenoids in 20 h. In relation the tocopherols, highlighted the presence of γ-tocopherol, except in the papaya oil. In 20 h, SMe and SPa still showed high amounts of tocopherols, with 76 and 85% of retention, respectively. With the thermoxidation, the amounts of phytosterols decreased. A great potential can be verified for the use of papaya and melon seed oils, in order to increase the oxidative stability of the soybean oil.

The antioxidant activity from basil ethanol extract, the effect on oxidative stability, total polar compounds, tocopherols levels and fatty acid profile in soybean oil under thermoxidation were evaluated. The basil leaves were dried in lyophilizer, ground and subjected to extraction with ethanol. The soybean oil (SO), soybean oil with 50 mg/kg of tert‐butylhydroquinone (TBHQ), soybean oil with 3,000 mg/kg of extract (BE) and soybean oil with 3,000 mg/kg of extract and 50 mg/kg of TBHQ (mixture) treatments were subjected to 180 ± 5C for 20 h. Oil samples were taken at 0, 10 and 20 h and subjected to analysis. The addition of the basil extract increased oxidative stability and resulted in lower formation of total polar compounds. Although the content of tocopherols and polyunsaturated fatty acids decreased over the course of heating, their values remained higher than the SO treatments. Synergistic effect was not observed in the mixture treatment. Practical Applications Antioxidants are important ingredients in food processing because they have the capacity to protect foods containing oils and fats, from damage caused by free radicals and reactive oxygen species. Synthetic antioxidants are widely used in the food industry; however, their utilization has been questioned due to toxicity. Therefore, there is a growing interest in the use of natural antioxidants to reduce or replace the synthetic antioxidants. Several species of the Lamiaceae family are used in cooking, medicine and by the pharmaceutical industry, standing out is basil. Being rich in compounds with high antioxidant activity, basil extract can be used to replace synthetic antioxidants used in vegetable oils.

The rancidity of vegetable oils is considered one problem in the food industry, thus, are added antioxidants in food. The objective of this study was to investigate the antioxidant effect of oregano and thyme extracts in soybean oil under thermoxidation. Soybean oil containing 3,000 mg/kg of oregano and thyme oleoresins and the mixture of both, as well as soybean oil containing tertbutylhydroquinone (TBHQ; 50 mg/kg) and soybean oil free of were subjected to thermoxidation. Then, the physicochemical properties and fatty acid profile were evaluated. Oregano and thyme oleoresins applied separately presented a higher protective effect, inhibiting a greater formation of polar compounds than the antioxidant TBHQ, indicating that the addition of 3,000 mg/kg has ensured a better oxidative protection than the synthetic antioxidant. The increase in the concentration of oleoresins by mixing thyme and oregano extracts has given a higher protective effect. PRACTICAL APPLICATIONSOxidation is a problem encountered in the food industry, whereas food-based oils are susceptible to oxidative degradation. To avoid this, the industry uses antioxidants that can be natural or synthetic. The use of natural antioxidants has increased because of the high demand for healthful food products and proven toxicity of some synthetic antioxidants. Many spices and herbs, such as those belonging to the family Lamiaceae, show antioxidant activity highlighting the oregano and thyme. Thus, being rich in compounds with high antioxidant activity, these extracts can be used to replace synthetic antioxidants used in vegetable oils. Oxidative StabilityThe oxidative stability was determined according to the Official Method Cd 12b-92 (AOCS 2009), employing the Rancimat instrument (model 743, Metrohm). The test is ANTIOXIDANT EFFECT IN SOYBEAN OIL N. JORGE, C.M. VERONEZI and P.V. DEL RÉ

Each year, the consumption of vegetable oils increases gradually. Some oils, such as chia, sesame, and quinoa, are consumed due to the nutritional properties and health promoters that have been recognized in their components. Based on this premise, the present study aimed to characterize chia (Salvia hispanica), sesame (Sesamum inducum), and quinoa (Chenopodium quinoa) oils, in order to enable their applications in the development of new food products. Chia oil presented higher degradation, as it stood out with higher amounts of free fatty acids (4.46%) and peroxide value (18.35 meq/kg). It is an oil that is rich in polyunsaturated fatty acids (75.47%), and, consequently, with high refractive index (1,475) and iodine value (192.86 g/100 g). Quinoa oil stood out for its higher oxidative stability (17.55 h) and higher amount of phenolic compounds (190.84 mg/100 g). Sesame and quinoa oils showed no significant difference for carotenoids, but sesame oil had higher content of total tocopherols (656.50 mg/kg). Thus, the oils can be used in technological processes and/ or in the formulation of new food products, in order to their increase the nutritional value.

No abstract

A presente revisão de literatura evidencia a importância dos carotenoides, como compostos bioativos e seu potencial para aplicação em alimentos funcionais. Foram detalhadas a origem, as características químicas e as fontes de carotenoides. Também foram estudadas as metodologias mais utilizadas na sua quantifi cação e qualifi cação, incluindo a espectrofotometria, a espectrometria de massa, a cromatografi a a líquido de alta efi ciência, a cromatografi a a gás e a colorimetria. Recomenda-se a ingestão de abóboras por apresentarem quantidades relevantes de importantes carotenoides, como α-caroteno, β-caroteno e luteína. PALAVRAS-CHAVES: CAROTENOIDES; ABÓBORAS; ANTIOXIDANTES; PRÓ-VITAMINA A.