Assessment of the critical period for the effect of intercepted solar radiation on sunflower oil fatty acid composition

Forty lactating Comisana ewes were either exposed to or protected from solar radiation and fed either in the morning or afternoon during summer in a Mediterranean climate. Individual milk samples were taken on days 7, 21 and 42 of the study period to determine fatty acid composition by gas chromatography. Exposure to solar radiation resulted in higher proportions of short-chain and saturated fatty acids in milk, primarily because of increased contents of caproic, capric, lauric, myristic and stearic acids (by 3–18%), and decreased contents of oleic, linoleic and linolenic acids (by 2–9%). As a consequence, the long to short chain and the unsaturated to saturated fatty acid ratios were significantly higher by 4 and 13% respectively in the milk of the protected ewes compared with that of the exposed animals. Provision of shade also led to an increase in the 18[ratio ]0+18[ratio ]1 to 16[ratio ]0 ratio, and to a decrease in the 12[ratio ]0+14[ratio ]0+16[ratio ]0 fatty acid group, which are regarded as reliable indexes of the nutritional property of dietary fat in reducing cholesterol levels in human plasma. Feeding time had little impact on milk fat. Our findings suggest that high ambient temperature may markedly modify the lipid composition of ewe milk and that provision of shade, but not feeding management, can improve the milk fatty acid profile in dairy sheep raised in hot climates.

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Ripening and Solar Exposure Alter Polar Lipid Fatty Acid Composition of `Honey Dew' Muskmelons

HortScience ◽

10.21273/hortsci.25.10.1262 ◽

1990 ◽

Vol 25 (10) ◽

pp. 1262-1264 ◽

Cited By ~ 7

Author(s):

Charles F. Forney

Keyword(s):

Fatty Acids ◽

Fatty Acid Composition ◽

Fatty Acid ◽

Solar Radiation ◽

Acid Composition ◽

Polar Lipid ◽

Unsaturated Fatty Acids ◽

Polar Lipids ◽

Solar Exposure ◽

Lipid Fatty Acid

Polar lipids were extracted from immature through overripe `Honey Dew' muskmelons (Cucumis melo L.) that were exposed to high or low levels of solar radiation. Fatty acid composition of the polar lipids changed and the percentage of unsaturated fatty acids increased as fruit ripened. The percentage of monounsaturated fatty acids palmitoleic and oleic acid as a percent of total fatty acids increased from 8% in melons of minimum maturity to >50% in overripe melons. Also, the ratio of unsaturated to saturated fatty acids increased from 2.2 to 5.0. Total polar lipid fatty acid compostion from middle mesocarp tissue (flesh) did not change as much during ripening as the polar lipid composition from the epidermis (peel). Peel tissue from the top of melons relative to the ground had unsaturation ratios of C18 fatty acids and C16 fatty acids 33% and 62% greater, respectively, than peel from the bottom of the melon. Melons of minimum maturity exposed to solar radiation had significantly more unsaturated C18 fatty acids than shaded melons. Increase in the percentage of unsaturated polar lipid fatty acids in `Honey Dew' melons may relate to increases in chilling tolerance reported to occur with ripening and solar exposure.

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Ruminal parameters and fatty acid composition of omasal digesta and milk in cows fed sugarcane-based diets supplemented with sunflower oil

Semina Ciências Agrárias ◽

10.5433/1679-0359.2020v41n5supl1p2317 ◽

2020 ◽

pp. 2317-2334

Author(s):

Fernando César Ferraz Lopes ◽

Shirley Motta de Souza ◽

Sebastião de Campos Valadares Filho ◽

Marco Antônio Sundfeld da Gama ◽

Luciana Navajas Rennó

Keyword(s):

Fatty Acids ◽

Fatty Acid Composition ◽

Fatty Acid ◽

Acid Composition ◽

Sunflower Oil ◽

Milk Fat ◽

Volatile Fatty Acids ◽

Linear Increase ◽

Neutral Detergent Fiber ◽

Apparent Digestibility

This study evaluates the intake and digestion of nutrients, parameters of rumen fermentation and degradation, omasal digesta and milk fatty acid composition, productive performance, and the concentration of serum metabolites in cows fed 600 g kg-1 sugarcane-based diets containing 0 (control), 15, 30, and 45 g kg-1 sunflower oil (SO) on a dry matter (DM) basis. Four rumen-cannulated Holstein x Gyr cows yielding 15±5 kg day-1 with 110±10 days in milk were allocated in a 4 x 4 Latin square design. Data were analyzed using mixed models, and significant differences were declared at P < 0.05. There was no effect of SO on the intake and apparent digestibility of DM, crude protein, neutral detergent fiber (NDF) and nonfibrous carbohydrates, but there was a linear increase in the intake and digestibility of ether extract. Dietary SO levels did not alter the ruminal degradability parameters for DM and NDF, rumen pH and contents of ammonia N, acetate, propionate and volatile fatty acids. Milk fat content and yield were linearly decreased, whereas a linear increase in milk protein content was observed in response to increasing levels of SO, but with no effect on milk yield. Linear reductions in palmitic and ?-linolenic acid contents, a linear increase in trans-10 C18:1 and elaidic acids, and a quadratic effect on vaccenic and rumenic acids were observed in omasal digesta of cows fed increasing levels of SO. Overall, up to 45 g kg-1 SO can be included on DM of chopped sugarcane-based diets without reducing consumption, apparent digestibility and rumen degradability of DM and fiber. Supplementing chopped sugarcane-based diets with 30 to 45 g kg-1 SO (DM basis) promotes milk fat depression due to the inhibition of mammary lipogenesis by specific rumen-derived fatty acid intermediates of the biohydrogenation of unsaturated C18 fatty acids. The inclusion of 15 to 45 g kg-1 SO in chopped sugarcane-based diets improves the nutritional quality of milk fat, with increases in the levels of oleic, vaccenic and rumenic acids, beneficial to human health, and a reduction in the levels of the hypercholesterolemic lauric, myristic and palmitic acids.

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Quality parameters of different oils and fried foods after repeated deep-fat frying

Meso ◽

10.31727/m.22.6.3 ◽

2020 ◽

Vol 22 (6) ◽

pp. 460-474

Author(s):

Tomaž Polak ◽

Lea Demšar ◽

Nežka Lazar ◽

Iva Zahija ◽

Mateja Lušnic Polak

Keyword(s):

Fatty Acid Composition ◽

Fatty Acid ◽

Acid Composition ◽

Sunflower Oil ◽

Peroxide Number ◽

Deep Frying ◽

Deep Fat Frying ◽

Chicken Nuggets ◽

Frying Process ◽

Fried Foods

The aim of present study was to investigate the quality, stability and suitability of different frying oils (coconut, palm, frying mix, rapeseed and sunflower oil), the quality and stability of breaded and fried foods (chicken nuggets) and the applicability and suitability of certain parameters (fat absorption, acid number, peroxide number and thiobarbituric acid (TBA) number, fatty acid composition and acrylamide content) as well as sensory attributes to control the repeated deep-(fat) frying process. Three repeated deep-frying processes affected the hydrolytic and oxidation stability (increase in the peroxide number and TBA number), the sensory properties (darkening of the oil colour, occurrence of odd smell and aroma as well as rancidity in oils) and the fatty acid composition of oil and fried chicken nuggets, and the acrylamide content in the nuggets (from the second deep-frying process onwards). All oils used in study were suitable for deep-frying; in terms of stability, coconut oil (followed by sunflower, palm, frying mix and rapeseed oil) was most suitable; in terms of fatty acid composition, the frying mix, rapeseed and sunflower oil were most suitable; and in terms of acrylamide formation and sensory quality, coconut and palm oil were most suitable.

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