Carvacrol, sabinene hydrate and thymol could be used as an alternative to synthetic antioxidants for preserving the quality of roasted sunflower seeds.

Summary This study reported the chemical composition, phenolic content, antioxidant and anti‐lipase activity of oregano and Lippia essential oils. The major compounds found in oregano essential oil were γ‐terpinene (32.10%), α‐terpinene (15.10%), p‐cymene (8.00%) and thymol (8.00%). In Lippia essential oil, α‐limonene (76.80%) and 1,8‐cineole (4.95%) represented the major compounds. Oregano essential oil had higher phenolic content (12.47 mg gallic acid mL−1) and DPPH scavenging activity (IC50 0.357 μg mL−1) than Lippia essential oil (7.94 mg gallic acid mL−1 and IC50 0.400 μg mL−1, respectively). Both essential oils had similar antioxidant indexes (about 1.2) determined by Rancimat. Moreover, oregano essential oil had also higher anti‐lipase activity (IC50 5.09 and 7.26 μg mL−1). Higher phenolic content in the essential oils was related with higher scavenging and anti‐lipase activities. Oregano and Lippia essential oils could be used as natural antioxidants on food products.

These results indicate that high-oleic Granoleico kernels provide peanut paste with higher protection against lipid oxidation.

The purpose of this work was to determine chemical composition and antioxidant activity of essential oil of different oregano species from Argentina: 'Cordobes', 'Criollo', 'Mendocino' and 'Compacto'. The essential oil composition was determined by gas-liquid chromatography and mass spectrometry. Scavenging activity was analysed by DPPH test. The antioxidant activity of the essential oils was determined by an accelerated oxidation test in canola oil. Thirty-nine compounds were identified in the oregano essential oils. The oregano species showed differences in their chemical composition, radical scavenging activity and antioxidant activity. The main compounds in the studied oregano species were thymol and trans-sabinene hydrate followed by c-terpinene, terpinen-4-ol and a-terpinene. The oregano, 'Criollo', was rich in c-terpinene and had lower thymol and trans-sabinene hydrate and higher a-terpinene and carvacrol contents than the other oregano species. 'Mendocino' had higher trans-sabinene hydrate and limonene than the other oregano species. 'Cordobes' and 'Compacto' had higher thymol content, radical scavenging activity and antioxidant activity in canola oil.

Peanut products are susceptible to develop rancid and off-flavours through lipid oxidation. Preservation of these products is one of the problems in the peanut industry. The purpose of this work was to determine the sensory and chemical stability of roasted peanuts (RP) coated with different edible coatings: carboxymethyl cellulose (RP-CMC), methyl cellulose (RP-MC) or whey protein (RP-WPI) during storage. Sensory attributes and chemical indicators (peroxide and p-anisidine values, and conjugated dienes) of lipid oxidation were measured during storage. Chemical indicator values and intensity ratings of oxidised and cardboard flavours had lower increase in RP-CMC, RP-MC and RP-WPI during storage than in RP, whereas roasted peanutty flavour showed a lower decrease. The stability of RP-CMC is about a double longer with respect to RP. These results indicate that edible coatings preserve the sensory properties of roasted peanuts. Carboxymethyl cellulose exhibited the best protecting effect on this product.

The objective was to evaluate the stability of sensory and chemical parameters in roasted sunflower seeds supplemented with oregano and poleo essential oils; and the consumer acceptability of this product. Four samples were prepared: plain roasted sunflower seeds (Control = RS-C), and sunflower seeds added with oregano (RS-O) or poleo (RS-P) essential oils or BHT (RS-BHT). Consumer acceptance was determined on fresh samples. The overall acceptance averages were 6.13 for RS-C, 5.62 for RS-P, and 5.50 for RS-O (9-point hedonic scale). The addition of BHT showed greater protection against the oxidation process in the roasted sunflower seeds. Oregano essential oil exhibited a greater antioxidant effect during storage than poleo essential oil. Both essential oils (oregano and poleo) provided protection to the product, inhibiting the formation of undesirable flavors (oxidized and cardboard). The antioxidant activity that presents essential oils of oregano and poleo could be used to preserve roasted sunflower seeds.

Hake (Merluccius hubbsi) is the most important fish of Argentinean industry. The preservative effects of an oregano essential oil (EO) nanoemulsion (NE) on hake burgers (FB) during 15 days at 4°C were studied. Fatty acids determined by gas chromatography coupled with mass spectrometry (CG-MS), volatile compounds determined by solid phase microextraction (SPME) coupled with CG-MS, total volatile basic nitrogen (TVBN), and microbial count was measured. ANOVA and DCG tests were performed. After 14 days, significant differences were detected among samples (P ≤ 0.05). FB with EO (EO-FB) and FB with NE containing EO (NEEO-FB) had the highest content of EPA (eicosapentaenoic acid) (191.82 and 198.42 g kg À1 ) and DHA (docosahexaenoic acid) (107.97 and 110.87 g kg À1 , respectively). Also, NEEO-FB had the lowest microbial count (7 log CFU g À1 ). The incorporation of the oregano essential oil into a nanoemulsion improves the preserving activity in hake fish burgers. Storage study and chemical analysis of stored hake burgersHakes (total 9 kgs) were purchased fresh from a local market. Pure EO, nanoemulsion containing EO (NE-EO) Oregano nanoemulsion: hake burger quality preserver C. M. Asensio et al. 150 Oregano nanoemulsion: hake burger quality preserver C. M. Asensio et al.

The purpose of this work was to determine the oxidative stability of roasted peanuts coated with prickly pear and algarrobo pod syrups. General composition, total phenolic compounds and radical scavenging activity were determined on prickly pear and algarrobo pod syrups. Chemical (peroxide value) and descriptive analyses were performed on samples of roasted peanuts, roasted peanuts with prickly pear syrup and roasted peanuts with algarrobo pod syrup stored at 23C for 112 days to determine protective effect of the syrup coating on the product stability. Prickly pear syrup showed higher moisture, protein, ash, lipid, phenolic compound content and lower carbohydrate content than algarrobo pod syrup. Prickly pear syrup also showed higher antioxidant activity (diphenyl picryl hydrazyl inhibition). Peroxide value, oxidized and cardboard intensity flavors increased and roasted peanutty intensity attribute decreased across the storage time for all studied products. Therefore, the addition of syrup coating provided protection against lipid oxidation. Peroxide value reached 10 meqO2/kg after 8.5 days in roasted peanuts, 20.7 days in roasted peanuts coated with prickly pear syrup and 29.5 days in roasted peanuts coated with algarrobo pod syrup at 23C. In consequence, algarrobo pod syrup had the highest protective effect in the roasted peanut product stored at room temperature. PRACTICAL APPLICATIONS The results of this work show advantages for using coatings that improve the stability of peanut products by making it more resistant to lipid oxidation and the development of rancid flavor. In this case, the edible coatings are elaborated using prickly pear and algarrobo pod syrups. These syrups could be applied on other similar food products with high lipid content to increase their shelf life and improve their stability, thus preventing loss of their sensory and nutritional quality.