Addition Of Olive Oil Research Articles

Laboratory Bioassays of Vegetable Oils as Kairomonal Phagostimulants for Grasshoppers (Orthoptera: Acrididae)

Vegetable oils have kairomonal attractant properties to grasshoppers primarily due to the presence of linoleic and linolenic fatty acids. These fatty acids are dietary essentials for grasshoppers and, once volatilized, can be detected by the insects' olfactory receptors. A laboratory bioassay method has been developed to identify vegetable oils that have fatty acid profiles similar to grasshoppers and that induce grasshopper attraction and feeding. Such oils could be useful kairomonal adjuvants and/or carriers for acridicide formulations. Three sets of laboratory bioassays demonstrated that the addition of a standard aliquot of different vegetable oils resulted in varying degrees of grasshopper feeding on otherwise neutral substrates. Addition of olive oil stimulated the greatest feeding in all three sets of assays, regardless of the age of the tested insects. Furthermore, addition of canola or flax oils markedly enhanced grasshopper feeding. These three oils--i.e., olive, canola, and flax oil--proved to be the best performing grasshopper stimulants. A second group of oils included rapeseed-flax mix and rapeseed oils; however, their performance was not as consistent as oils in the first group--especially with regard to nymphal feeding. A third group of oils consisted of soybean, corn, peanut, and sunflower oil. Theoretical expectations regarding these oils varied wildly, suggesting that the results of a single bioassay should be cautiously interpreted as being negative.

올리브유 및 대두유를 첨가한 돼지등심 분쇄육의 냉장 중 품질변화

This study was carried out to investigate the effect of the addition of olive and soybean oil on the color, water holding capacity, cooking loss, increase rate of thickness, decrease rate of diameter, pH, VBN content and TBARS value of ground pork loin during cold storage for 15 days. Ground pork loin were prepared by three types such as ground pork loin containing 20% pork fat (GP-P), ground pork loin containing 20% olive oil (GP-O) and ground pork loin containing 20% soybean oil (GP-S). The L * (lightness) and b * (yellowness) value of GP-P, GP-O and GP-S were not significantly different during storage, and the L * , a * and b * value of GP-P were higher than those of GP-O and GP-S (p＜0.05). The water holding capacity tended to increase along with storage period, the water holding capacity of GP-P was higher than that of GP-O and GP-S. Also, the cooking loss of GP-P was lower than that of GP-O and GP-S (p＜0.05). The increase rate of thickeness by cooking increased along with storage period, but the decrease rate of diameter was tend to decreased with increase in storage period (p＜0.05). The pH of all ground pork loins decreased until storage at 5 days, but increased at 15 days (p＜0.05). The VBN content of all ground pork loins increased along with storage period, and the VBN content of GP-P was higher than that of GP-O and GP-S (p＜0.05). The TBARS value of all ground pork loins increased along with storage period; also, the VBN content of GP-P was the highest among all ground pork loins and GP-O was the lowest among all ground pork loins (p＜0.05).

돼지지방, 올리브유 및 대두유를 첨가한 분쇄돈육의 품질 및 기호성

본 연구는 돼지지방, 올리브유 및 대두유를 첨가한 분쇄돈육의 품질 및 기호성을 검토하기 위하여 돼지지방을 첨가한 분쇄돈육(GP-P), 올리브유를 첨가한 분쇄돈육(GP-O) 및 대두유를 첨가한 분쇄돈육(GP-S) 등 세 종류의 분쇄육을 제조하고 일반성분, 표면색깔, 지방산 조성, 보수력, pH, VBN 함량, TBARS값 및 순위법에 의한 기호성을 측정하였다. 수분, 조단백질, 조지방 및 조회분 함량은 GP-P, GP-O 및 GP-S 사이에 통계적 유의성이 없었다. <TEX>$L^{*}$</TEX>(명도), <TEX>$a^{*}$</TEX>(적색도) 및 <TEX>$b^{*}$</TEX>(황색도)값은 GP-P가 GP-O 및 GP-S보다 유의하게 높았다(p<0.05). 가장 많이 함유된 포화지방산은 palmitic acid로서 GP-P(24.384%)가 GP-O(15.611%) 및 GP-S(14.423%)보다 유의하게 높았다(p<0.05). 불포화지방산의 경우 GP-P(43.773%)및 GP-O(65.040%)는 oleic acid가 가장 많았으며, GP-S는 linoleic acid(40.762%)가 가장 많이 함유되어 있었다. 보수력은 GP-P가 GP-O 및 GP-S보다 높았으며, pH는 GP-S가 GP-P및 GP-O보다 높았고, VBN 함량 및 TBARS값은 GP-P가 GP-O및 GP-S보다 유의하게 높았다(p<0.05).가열하지 않은 분쇄돈육의 색깔은 GP-O 및 GP-S가 GP-P보다 우수하였으나(p<0.05), 향기는 시료들 사이에 통계적 유의성이 없었다. 가열 분쇄육의 경우, 향기는 시료들 사이에 유의한 차이가 없었으며, 맛, 조직감 및 전체적인 기호성은 GP-S가 가장 우수하였고(p<0.05), 다즙성은 GP-O 및 GP-S가 GP-P보다 우수하였다(p<0.05). This study was carried out to investigate the effects of addition of pork fat, olive oil and soybean oil on the quality and sensory of ground pork meat. The samples consisted of the ground pork meat containing 20% pork fat (GP-P), 20% olive oil (GP-O), and 20% soybean oil (GP-S). The chemical composition, surface color, fatty acid composition, water hold-ing capacity, pH, VBN content and TBARS value were determined for the ground pork meat as the quality characteristics, and the sensory score were also evaluated. The moisture, crude protein, crude fat and crude ash content were not different among the GP-P, GP-O and GP-S. The <TEX>$L^{*}$</TEX>(lighaess), <TEX>$a^{*}$</TEX>(redness) and <TEX>$b^{*}$</TEX>(yellowness) of /GP-P were higher than those of the GP-O and GP-S (p<0.05). Palmitic acid was the most abundant among saturated fatty acids, and palmitic acid content of GP-P (24.384%)was higher than that of the GP-O (15.611%) and GP-5 (14.423%). In case of unsaturated fatty acids, oleic acid of GP-P (43.773%) and GP-O (65.040%) were the highest, linoleic. acid for GP-5 (40.762) was the highest. The water holding capacity of GP-P was higher than that of the GP-0 and GP-5, the pH of GP-S was higher than that of the GP-P and GP-O, and the VBN content and TBARS value of GP-P was higher than that of the GP-O and GP-5 (p<0.05). The raw color of GP-0 and GP-S were higher than that of the GP-P (p<0.05), however the raw aroma was not different among the samples. In case of roasted ground pork meat, the aroma was not different among the samples, the taste, texture and palatability or GP-S were the highest among the samples, and the juiciness of GP-O and GP-S were higher than that of the GP-P(p<0.05).

Effect of plant oil and surfactant on the production of mycelial biomass and polysaccharides in submerged culture of Grifola frondosa

Effects of various plant oil addition and surfactant addition at different stages of cell growth phase on the cell growth and production of bioactive metabolites, such as exopolysaccharide (EPS) and intracellular polysaccharide (IPS) in the submerged culture of Grifola frondosa were studied with 2% glucose medium. Olive, safflower seed, soy and sunflower oil were favorable plant oil sources to the mycelial growth of G. frondosa. The highest cell growth (∼12.64 ± 0.47 g/l cell dry weight) can be obtained on day 13 of cultivation in the medium containing 1% all the plant oil sources. EPS production was slightly enhanced by olive oil but significantly inhibited by safflower seed oil and sunflower oil after 13 days of cultivation. With 4% glucose, 0.5% plant oils were selected to add on 0-, 3-, 7-, and 9-day of cultivation to exam the effect on the cell growth at different stages. Amongst four plant oil sources examined, cell growth yielded relatively high mycelial biomass (11.22 ± 1.14 g/l) and that was achieved in 4% glucose medium with 0.5% soybean oil. The higher EPS production and slightly lower cell growth were found in 4% glucose media; the maximum EPS production was 2.248 ± 0.107 g/l found in 4% glucose media with olive oil addition. Tween 80 and Span 80 addition had shown to increase cell growth and the maximal cell concentration of 9.10 ± 0.80 g/l was obtained with 1% Span 80 addition. Both EPS and IPS production were found to decrease with all the tested concentrations of Tween 80 and Span 80 addition. Span 80 added at the vegetative growth phase in 4% glucose media yielded the highest mycelial biomass of G. frondosa (8.95 ± 0.57 g/l); meanwhile Tween 80 added at the beginning cultivation had resulted in the highest EPS production (1.451 ± 0.098 g/l). Tween 20 and Span 20 addition were shown to have serious inhibition on cell growth of G. frondosa and also on polysaccharides production. The results obtained were useful in better understanding the regulation and optimization of G. frondosa culture for efficient production of cell mass and polysaccharides in the submerged culture.

Bioaccessibility of carotenes from carrots: Effect of cooking and addition of oil

Food processing and occurrence of dietary lipids are believed to be important and limiting factors for carotenoid bioavailability in humans. In the present study the isolated and combined effects of household cooking and addition of olive oil on the bioaccessibility of carotenes from carrots have been investigated. Although thermal treatment during cooking showed to have a negative impact on the carotenoid content, a positive effect on the micellarisation of carotenes and therefore on their bioaccessibility was found. Carotenes transferred to the digests were micellarised to a higher extent from cooked carrots (52%) than from crude carrots (29%). Addition of olive oil to carrot samples during cooking and before application of the in vitro digestion model had a marked positive effect on the release of carotenes, although the design of the model did not allow the correct estimation of this effect. The higher amounts of micellarised carotenes (80%) were found in the digest prepared from cooked carrots containing 10% olive oil. In general, the inclusion of olive oil during cooking increased the carotenoid extraction and micellarisation in a dose-dependent fashion. Although β-carotene and α-carotene were affected in a similar way by the cooking process, α-carotene appeared to be more efficiently incorporated into the micelles when olive oil was added to the samples. In conclusion, both processing and mainly lipid content (cooking oil in this case) significantly improve carotenoid bioaccessibility from carrots, and therefore may increase bioavailability in humans. The consumption of carotenoid-rich foods such as fruits and vegetables has been associated with a decrease of the risk of developing certain types of degenerative and chronic diseases. Processing of food and the interaction of carotenoids with lipophilic food components or ingredients may modify the amount of the released pigment from the food matrix, and therefore potentially increase or decrease their bioavailability. For this purpose, in the present study we have investigated the effects of cooking and presence of olive oil on the release of carotenes from carrots (as a model food) and their incorporation into absorbable micelles, the bioaccessibility. From the industrial point of view, a better understanding of the factors governing the release of carotenoids and other active components from vegetable foods is of great importance with the aim of optimising the manufacturing processes.

Full Length Article

Acute Effects of High-Fat Meals Enriched With Walnuts or Olive Oil on Postprandial Endothelial Function Berenice Cortés, Isabel Núñez, Montserrat Cofán, Rosa Gilabert, Ana Pérez-Heras, Elena Casals, Ramón Deulofeu, Emilio Ros A walnut diet has been shown to improve endothelial function in hypercholesterolemic subjects. In a crossover study in 12 normolipidemic controls and 12 hypercholesterolemic subjects, we compared the acute vasoactive effects of fatty meals (80 g fat, 35% energy as saturated fatty acids) enriched with either 25 g olive oil or 40 g walnuts. In both groups, brachial artery flow-mediated dilation worsened after the olive oil meal and improved after the walnut meal, but the circulating levels of oxidation and inflammation biomarkers decreased after either meal. Supplemental walnuts reverse the postprandial endothelial dysfunction associated with consumption of a fatty meal. We sought to investigate whether the addition of walnuts or olive oil to a fatty meal have differential effects on postprandial vasoactivity, lipoproteins, markers of oxidation and endothelial activation, and plasma asymmetric dimethylarginine (ADMA). Compared with a Mediterranean diet, a walnut diet has been shown to improve endothelial function in hypercholesterolemic patients. We hypothesized that walnuts would reverse postprandial endothelial dysfunction associated with consumption of a fatty meal. We randomized in a crossover design 12 healthy subjects and 12 patients with hypercholesterolemia to 2 high-fat meal sequences to which 25 g olive oil or 40 g walnuts had been added. Both test meals contained 80 g fat and 35% saturated fatty acids, and consumption of each meal was separated by 1 week. Venipunctures and ultrasound measurements of brachial artery endothelial function were performed after fasting and 4 h after test meals. In both study groups, flow-mediated dilation (FMD) was worse after the olive oil meal than after the walnut meal (p = 0.006, time-period interaction). Fasting, but not postprandial, triglyceride concentrations correlated inversely with FMD (r = −0.324; p = 0.024). Flow-independent dilation and plasma ADMA concentrations were unchanged, and the concentration of oxidized low-density lipoproteins decreased (p = 0.051) after either meal. The plasma concentrations of soluble inflammatory cytokines and adhesion molecules decreased (p < 0.01) independently of meal type, except for E-selectin, which decreased more (p = 0.033) after the walnut meal. Adding walnuts to a high-fat meal acutely improves FMD independently of changes in oxidation, inflammation, or ADMA. Both walnuts and olive oil preserve the protective phenotype of endothelial cells.

Acute Effects of High-Fat Meals Enriched With Walnuts or Olive Oil on Postprandial Endothelial Function

We sought to investigate whether the addition of walnuts or olive oil to a fatty meal have differential effects on postprandial vasoactivity, lipoproteins, markers of oxidation and endothelial activation, and plasma asymmetric dimethylarginine (ADMA). Compared with a Mediterranean diet, a walnut diet has been shown to improve endothelial function in hypercholesterolemic patients. We hypothesized that walnuts would reverse postprandial endothelial dysfunction associated with consumption of a fatty meal. We randomized in a crossover design 12 healthy subjects and 12 patients with hypercholesterolemia to 2 high-fat meal sequences to which 25 g olive oil or 40 g walnuts had been added. Both test meals contained 80 g fat and 35% saturated fatty acids, and consumption of each meal was separated by 1 week. Venipunctures and ultrasound measurements of brachial artery endothelial function were performed after fasting and 4 h after test meals. In both study groups, flow-mediated dilation (FMD) was worse after the olive oil meal than after the walnut meal (p = 0.006, time-period interaction). Fasting, but not postprandial, triglyceride concentrations correlated inversely with FMD (r = -0.324; p = 0.024). Flow-independent dilation and plasma ADMA concentrations were unchanged, and the concentration of oxidized low-density lipoproteins decreased (p = 0.051) after either meal. The plasma concentrations of soluble inflammatory cytokines and adhesion molecules decreased (p < 0.01) independently of meal type, except for E-selectin, which decreased more (p = 0.033) after the walnut meal. Adding walnuts to a high-fat meal acutely improves FMD independently of changes in oxidation, inflammation, or ADMA. Both walnuts and olive oil preserve the protective phenotype of endothelial cells.

Effect of olive oil on the production of mycelial biomass and polysaccharides of Grifola frondosa under high oxygen concentration aeration

In this research, the factors of oxygen concentration (21%, 30%, and 40%) and olive oil addition were studied on the production of mycelial biomass and polysaccharides of Grifola frondosa in a 5-L jar fermentor. The 40% oxygen was found to inhibit both cell growth and polysaccharide production with a higher rate of glucose consumption. The highest cell concentration was found at 9.29 g/L at day 9 with 1 vvm at 21% O 2. With 30% O 2 the inter-cellular polysaccharide (IPS) level increased earlier than 21% O 2 and reached the maximum concentration at day 8 with 21.9 mg/g. On the other hand, 21% O 2 reached the maximum concentration at day 11 with 19.5 mg/g. With 1% olive oil addition in 21% O 2 and 40% O 2, the production of mycelial biomass was enhanced and increased to 10.1 and 14.9 g/L, respectively, after 9 days’ cultivation. And the extra-cellular polysaccharide (EPS) production increased from 0.7–0.9 g/L to 2.24 g/L and 3.00 g/L at day 13 with 21% O 2 and 40% O 2 aeration, respectively. In addition, the IPS increased rapidly and reached the maximum level of 28.2 mg/g at day 7 and this level remained till day 13 through the whole fermentation. The scanning electron microscopy (SEM) of the mycelia and cell activity were studied to investigate the role of olive oil under high concentration of oxygen aeration. The vegetative cell was observed from both the 7-day-old culture and the 9-day-old culture from both 21% O 2 and 40% O 2 with olive oil addition. With 40% O 2 aeration, low growth activity and significant wrinkles appeared on the surface of mycelia on both 7-day-old culture and 9-day-old culture. The olive oil addition in media was observed to reduce the wrinkles appeared on the surface of mycelia under high concentration oxygen and made the cell be aging more slowly.

Lipase localization in Rhizopus oryzae cells immobilized within biomass support particles for use as whole-cell biocatalysts in biodiesel-fuel production

To identify the lipase responsible for the methanolysis activity of fungus whole-cell biocatalysts, the lipase localization of Rhizopus oryzae cells was determined. Western blot analysis showed that R. oryzae cells produce two types of lipase with different molecular masses of 34 and 31 kDa; the former (ROL34) was bound to the cell wall, whereas the latter (ROL31) was mainly bound to the cell membrane. It was found that cell immobilization within reticulated polyurethane foam biomass support particles strongly inhibits the secretion of membrane-bound lipase into the culture medium. An investigation of the relationship between ROL34 and ROL31 suggested that ROL31 originates from the cleavage of a 28-amino-acid residue at the N-terminus of ROL34. The addition of olive oil to the culture medium led to the retention of increased amounts of lipase within the cell. This phenomenon was further confirmed by an immunofluorescence labeling of hyphal cells. When cells were cultivated with various substrate-related compounds, such as olive oil and oleic acid, the intracellular methanolysis activity strongly correlated with the relative amounts of the membrane-bound lipase, which suggests that ROL31 localized in the membrane plays a crucial role in the methanolysis activity of R. oryzae cells.

Olive-mill wastewaters: a promising substrate for microbial lipase production

The present study investigated the valorization of olive-mill wastewater (OMW) by its use as a possible growth medium for the microbial production of extra-cellular lipase. To this end, strains of Geotrichum candidum (NRRL Y-552 and Y-553), Rhizopus arrhizus (NRRL 2286 and ISRIM 383), Rhizopus oryzae (NRRL 6431), Aspergillus oryzae (NRRL 1988 and 495), Aspergillus niger (NRRL 334), Candida cylindracea (NRRL Y-17506) and Penicillium citrinum (NRRL 1841 and 3754, ISRIM 118) were screened. All strains were able to grow on the undiluted OMW, producing extra-cellular lipase activity. C. cylindracea NRRL Y-17506 showed the highest lipase activity on all the typologies of OMW used. Its lipase production on OMW was markedly affected by the type of nitrogen source and was induced by the addition of olive oil. The highest activity (9.23 IU ml −1) of the yeast was obtained on OMW supplemented with NH 4Cl (2.4 g l −1) and olive oil (3.0 g l −1).

Enantioselective properties of induced lipases from Geotrichum

Production of lipase by three strains of Geotrichum candidum (DBM 4012, DBM 4013, DBM 4166) and one strain of Geotrichum ludwigii (DBM 48) in liquid medium was investigated under addition of olive oil, which has been used as activator of the activity. The activity of cell-bound and extracellular lipases was determined. The most remarkable growth of the cell biomass was also observed using a medium with peptone as a source of nitrogen. The highest specific activity of all activated lipases was found when the cell growth reached a constant level (stationary phase of growth). All activated lipases were used as biocatalysts of the hydrolytic resolution of racemic cis- or trans-isomers of 2-(4-methoxybenzyl)cyclohexyl acetates. Attention was paid to the stereochemical course of the reaction, i.e. to the determination of the optical purity of the products and, consequently, to the assignment of the absolute configuration and the determination of the conversion rate. The satisfactory results from the point of view of the chemical yields of the reaction and enantiomeric purity of the products were obtained when lipases from G. candidum DBM 4013 were used as biocatalysts of the hydrolysis of trans-isomer of 2-(4-methoxybenzyl)cyclohexyl acetate.

Influence of Dietary Lipids on Survival of Phyciodes phaon Butterflies (Lepidoptera: Nymphalidae)

The Phaon crescent butterfly, Phyciodes phaon (Edwards), can be reared by placing newly-eclosed larvae on a pinto bean-based artificial diet; however, the adults fail to reproduce. Addition of 10% (w/w) of freeze-dried leaves of the host plant, Phyla nodiflora (L.) Greene, to the artificial diet approximately doubled the number of adults produced, and females oviposited viable eggs. Addition of wheat germ oil, linseed oil, or olive oil to the artificial diet without host plant tissue also increased survival to the adult stage, but adult females failed to oviposit. Larvae and adults reared from the artificial diet with addition of any one of the oils contained a higher quantity of linolenic acid in their body lipids than those reared on the artificial diet without additional oil. Leaves of the larval host plant are especially rich in the polyunsaturated fatty acids, linoleic acid and linolenic acid; whereas, the pinto bean diet is relatively low in these fatty acids, especially linolenic acid. Addition of synthetic β-sitosterol, stigmasterol, and campesterol, the sterols identified in the host plant leaves, to the artificial diet improved neither larval nor adult survival, and adult females did not oviposit. The factor (or factors) present in host plant leaves and acquired during larval feeding that enables reproduction of adults remains to be identified.

Effect of locust bean/xanthan gum addition and replacement of pork fat with olive oil on the quality characteristics of low-fat frankfurters

The effects of reducing fat level from 20% to 12% and 9%, substituting pork fat with olive oil and adding locust bean/xanthan gum (0.5% and 0.6%) on emulsion stability, jelly and fat separation, processing yield, cook loss, texture and sensory characteristics of frankfurters were investigated and compared with control samples. Addition of locust bean/xanthan gum produced a significant increase in hydration/binding properties, characterised by lower cook losses, increasing yield, better emulsion stability and lower jelly and fat separation. The substitution of pork fat by olive oil did not affect these parameters. Indeed, results showed that reducing fat levels together with increasing moisture and locust bean/xanthan gum addition do not affect the sensory or textural properties, but olive oil addition produces a decrease in hardness and an increase in adhesiveness, however the overall acceptability was not affected.

Nutritional-pharmacological combinations--a novel approach to reducing colon cancer incidence.

Recent studies have suggested that n-9 fatty acids in olive oil prevent colon carcinogenesis while n-6 PUFA seems to activate this process. To evaluate the effects of nutritional-pharmacological combinations made up of olive or soy oil-based diets and the drug sulindac, on colon cancer incidence in a chemically induced (1,2-dimethylhydrazine, DMH) rat cancer model. Male rats were assigned to two different dietary regimes based on a standard murine defined diet (AIN-76A) containing either a low (4%) or high (15 %) concentration of olive or soy oil. Some groups also received sulindac in their food (80 mg/kg food) starting from the ninth week following the first DMH or vehicle administration. Oleic and linoleic acid reached higher levels in plasma and liver lipids when rats were fed high concentrations of olive or soy oil, respectively. Rats fed a low or high soy oil-based diet showed no significant difference in the number of aberrant crypt foci (ACF) in proximal or distal colon specimens. In contrast, rats fed a higher olive oil-based diet developed a significantly lower number of ACF than rats fed a low concentration of olive oil. Addition of sulindac reduced the number of ACF in rats fed the 4%, but not the 15%, soy oil diet. In contrast, the effect of sulindac was significant when combined with both the low and high concentrations of olive oil. High soy oil-based diet or DMH treatment upregulated colon expression of Bcl-2, but not that of cyclooxygenase-2 (COX-2). In contrast, olive oil dose-dependently downregulated the expression of both Bcl-2 and COX-2 in colonic mucosa and also abrogated the upregulation of Bcl-2 by DMH. Olive oil/sulindac combinations were effective in downregulating colonic mucosa Bcl-2 expression (with the 4% oil diet) and COX-2 expression (with the 15% oil diet). These effects were not observed in rats fed the soy oil/sulindac combinations. Caspase-3 activity in colonic mucosa was unaffected by soy oil or soy oil/sulindac combinations. The addition of olive oil, on the other hand, significantly enhanced colonic caspase-3 activity. Diets containing high levels of olive oil exert a significant protective effect from tumor development that is additive with the inhibitory effect of sulindac. These inhibitory effects are mediated by regulating the expression and activity of key proteins involved in prostaglandin-biosynthesis and apoptosis-induction pathways. It may be concluded that appropriate dietary-pharmacological combination can improve anti-tumor efficacy over either dietary or pharmacological intervention alone.

Effect of storage and packaging on fatty acid composition and oxidation in dry fermented sausages made with added olive oil and antioxidants

Dry fermented sausages produced by a partial substitution of pork backfat with pre-emulsified olive oil were manufactured and stored (2 and 5 months) using different packaging conditions (aerobic/vacuum piece/vacuum slices) in order to evaluate the intensity of the oxidation process. Also the effect of the addition of butylhydroxytoluene (BHT) and butylhydroxyanisole (BHA) to one of the modified batches was studied. Addition of olive oil, especially with antioxidants, was more effective than using vacuum storing methods in avoiding lipid oxidation during storage. After 5 months of storage at 4 °C, the combination of the increase in oleic acid and the preservation of PUFA by the antioxidant activity of the olive oil emulsion and antioxidants (when added), lead to better MUFA + PUFA/SFA ratios in olive oil containing sausages (1.90–1.98 g/100 g fatty acids) and particularly in antioxidants containing sausages (2.02–2.16 g/100 g) than in control ones (1.72 g/100 g). Vacuum packaging of the piece was the best method to minimise formation of lipid oxidation volatile compounds.

Effect of replacing beef fat with olive oil on quality characteristics of Turkish soudjouk (sucuk)

Four formulation of Turkish soudjouks were produced in three replicates by traditional methods as follows; one control (C) using 85% beef and 15% beef fat and three treatments by replacing 20, 40 and 60% of beef fat with virgin olive oil incorporated as pre-emulsified fat (PEF) with soy protein isolate (SPI), respectively. It was found that the moisture content and pH decreased while fat and ash content increased on the 21st day of fermentation and in the ripening period. Cholesterol content decreased depending on the amount of incorporated olive oil to the formulation, which shows the addition of olive oil in soudjouks reduces the cholesterol content ( P<0.05). TBA values were affected by the amount of incorporated olive oil and the highest TBA value was found for with the 60% olive oil replacement. Oleic and linoleic acid contents were high while other fatty acid contents were low for the 40 and 60% olive oil samples compared with controls. Sausages with 40% olive oil received high evaluation from the panel for appearance and texture but there was no significant difference ( P>0.05) between samples in the terms of color and general acceptability. It is concluded that replacement of beef fat with olive oil had a positive effect on sensory quality and on reducing the cholesterol content of soudjouks.

Effect of Fat Level and Partial Replacement of Pork Backfat with Olive Oil on the Lipid Oxidation and Volatile Compounds of Greek Dry Fermented Sausages

ABSTRACT: High‐ and reduced‐fat Greek fermented sausages were produced with 30% and 20% total fat in the initial formulation. The same products were manufactured with a partial replacement of pork backfat with 20% olive oil. The influence of the modification of the lipid fraction on the oxidation process was evaluated after 2 mo of storage. The reduction of fat increased thiobarbituric acid (TBA) values, total aldehydes, and typical lipid oxidation compounds (hexanal, 2‐hexenal, 2‐octenal). A significant decrease in oxidation was detected in batches containing olive oil, particularly in the sausages with the highest olive oil content. This addition decreased, in both fat level products, TBA values and hexanal, 2‐hexenal, 2,4‐hexadienal, benceneacetaldehyde, tt,2,4‐nonadienal, and pentadecanal. The addition of olive oil significantly increased monounsaturated fatty acids content.

Partial substitution of pork backfat with extra-virgin olive oil in ‘salami’ products: effects on chemical, physical and sensorial quality

The effects on chemical, physical and sensory quality of the partial substitution of pork backfat with extra-virgin olive oil were studied in ‘salami’ products. Four ‘salami’ formulations, with 15% total fat, were prepared, in which 0, 33.5, 50 and 66.5% of pork backfat was substituted with extra-virgin olive oil. The partial pork backfat substitution with extra-virgin olive oil did not substantially affect the chemical, physical and sensorial characteristics of products, with the exception of water activity and texture. With regard to both oxidation and loss of organoleptic quality, the addition of extra-virgin olive oil, rich in mono-unsaturated fatty acids, did not decrease the shelf-life. The difference between samples with and without extra-virgin olive oil was a piquant note detected in the oil-added ‘salami’. The formulation with 5% olive oil, corresponding to 33.3% substitution of pork backfat with olive oil, was judged best of all formulations. The results show that it is possible to produce this type of product, of good taste, similar to the traditional one, but with healthier features.

Olive Oil Prevents the Adverse Effects of Dietary Conjugated Linoleic Acid on Chick Hatchability and Egg Quality

Dietary conjugated linoleic acid (CLA) decreases yolk 18:1(n-9), induces chick embryonic mortality and alters egg quality. A study was conducted to determine whether olive oil would prevent these adverse effects of CLA. Hens (15 per treatment) were fed diets containing 0.5 g corn oil/100 g (CO), 0.5 g CLA/100 g (CLA), 0.5 g corn oil plus 10 g olive oil/100 g (CO + OO) or 0.5 g CLA plus 10 g olive oil/100 g (CLA + OO). After 74 d of feeding, hens were placed on CO for 10 d. Hens were artificially inseminated weekly. For hatchability studies, fertile eggs were collected daily, stored at 15 degrees C for 24 h and then incubated. After 6 d of feeding, embryonic mortality rates were 15, 100, 8 and 16% in the CO, CLA, CO + OO and CLA + OO groups, respectively. When CLA-fed hens were fed the CO diet, hatchability improved to that of the CO group within 7 d. For fatty acid analysis, three eggs were obtained at the 7 d of feeding. Relative CLA levels of yolk from CO-, CLA-, CO + OO- and CLA + OO-fed hens were 0.11 +/- 0.01, 1.91 +/- 0.16, 0.08 +/- 0.04 and 0.69 +/- 0.07 g/100 g fatty acids, respectively. The ratios of 16:0/16:1(n-7) and 18:0/18:1(n-9) of yolk from CLA-fed hens were approximately 1- and approximately 1.5-fold greater, respectively, compared with those fed CO. OO prevented CLA-induced increases in 16:0 and 18:0 and the decrease in 18:1(n-9) in yolk. Fertile eggs were stored at 4 degrees C for 2 or 10 wk and analyzed for pH or mineral levels. Dietary CLA caused abnormal pH changes of albumen and yolk when eggs were stored at 4 degrees C. The pH of yolk and albumen from CO-fed hens after 10 wk of storage was 6.12 +/- 0.12 and 9.06 +/- 0.03, respectively, versus 7.89 +/- 0.25 and 8.32 +/- 0.16, respectively, in eggs from CLA-fed hens. OO prevented CLA-induced abnormal changes in the pH of albumen and yolks. Eggs from CLA-fed hens had greater iron, calcium and zinc concentrations and lower magnesium, sodium and chloride concentrations in albumen relative to those from hens fed CO. OO prevented CLA-induced mineral exchange between yolk and albumen, presumably by reducing the yolk saturated fatty acids, which are believed to disrupt the vitelline membrane during cold storage. This study suggests that the adverse effects of CLA may be due to the increased level of saturated fatty acids. However, because the addition of olive oil also lowered egg CLA content, the direct role of egg CLA on egg hatchability and quality cannot be ruled out.

Possibility of improving the quality characteristics of olive‐pomace oil and enhancing its differentiation from refined olive‐pomace oil

An investigation was carried out to evaluate the oxidative and hydrolytic degradation of 37 olive-pomace oils marketed in southern Italy and to compare the results with those obtained from 10 deodorised olive-pomace oils representative of large stocks of oil obtained after the final step of refining. One aim of the research was to ascertain the quality characteristics of commercial olive-pomace oils; another was to verify whether the legally prescribed addition of virgin olive oil to refined pomace oil, so that the final product may be classified commercially as olive-pomace oil, was actually sufficient to justify upgrading. The analytical methods used were silica gel column chromatography and high-performance size exclusion chromatography. The data obtained showed that the final retail olive-pomace oils had a lower degree of oxidative degradation than the refined oils, as indicated by the lower values obtained when summing the proportions of triglyceride oligopolymers and oxidised triglycerides. Conversely, hydrolytic degradation, which was evaluated by determining diglycerides, proved to be the same in the two categories of oil. The proportions of virgin olive oil added are small, as indicated by the statistically indistinguishable values of triglyceride oligopolymers and free fatty acids obtained. The possibility of setting a limit to the amount of triglyceride oligopolymers present in the commercial category of olive-pomace oil has been considered. This limit would ensure standardisation of the level of oxidation and, consequently, of the quality of marketed oils and would enhance differentiation between olive-pomace oil and refined olive-pomace oil. © 2000 Society of Chemical Industry