Authors:R. Briones-Martínez, M. Juárez-Juárez, M. Oliver-Salvador, and M. Cortés-Vázquez
DSC was used to study the extent of denaturation of hemisphaericin and mexicain hydrolysates from corn gluten, soybean and
sunflower meals. It was observed that the defatted meals studied exhibited only one broad peak transition. The data obtained
demonstrated that the partial protein denaturation found with hemisphaericin or mexicain is correlated to modifications of
functional properties. The two enzymes display different modes of action, according to the protein source.
Authors:A. Zervou, V. Sinanoglou, G. Papadas, N. Thomaidis, D. Meimaroglou, and S. Miniadis-Meimaroglou
The effects of different frying methods (oil free, extra virgin olive oil and sunflower oil pan-fried) on proximate, neutral and polar lipid composition as well as the fatty acid content of Spicara smaris, a fish species commonly consumed by Mediterranean people, were determined. Pan-frying caused insignificant changes in proteins and polar lipids, whereas a significant (P<0.05) decrease in moisture and ash content, and a significant (P<0.05) increase in the neutral lipids and total sterol content could be detected after pan frying in extra virgin olive oil (EVOO) and sunflower oil. The loss of the individual phospholipid content was not significant during the pan-frying process, but its proportion was influenced by the uptake of the culinary fat. The absorption of oil medium in pan-fried, in EVOO, and in sunflower oil samples resulted in an alteration of their fatty acid profiles including a significant (P<0.05) increase of C18:1ω-9 and C18:2ω-6 ratios and a decrease of EPA, DHA percentages as well as of the ω-3/ω-6 ratio. All frying methods affected (P<0.05) lipid quality indices but their values could be considered satisfactory in terms of healthiness. Among the fried samples, the oil free fried samples also presented the poorest triglyceride and cholesterol content, and the greatest ω-3/ω-6 ratio, thus, they were found to present the most appropriate frying method for healthy eating.
Jacob, J., Lawlor, D. W. (1992): Dependence of photosynthesis of sunflower and maize leaves on phosphate supply, ribulose-1,5-bisphosphate carboxylase/oxygenase activity, and ribulose- 1,5-bisphosphate pool size
Authors:G. Szöllőskei, L. Wagner, Stefánia Németh, and F. Husvéth
In this experiment sunflower oil, soybean oil and fish oil were incubated in rumen-fistulated adult ewes (n = 5) to study conjugated linoleic acid (CLA) production in the rumen. The individual oils were incubated in nylon bags in the rumen on perlite carrier (40% oil, 60% carrier) over a period of 2, 4, 6, 8, 10 and 12 h for all treatments. During the incubation of each oil primarily the formation of the cis-9, trans-11 isomer of CLA could be observed. Both sunflower and soybean oils showed similar changes in the rumen. After the incubation of these two vegetable oils the proportion of linoleic acid decreased significantly as the duration of incubation increased in the rumen. These changes were accompanied by a significant increase in the amount of cis-9, trans-11 CLA. However, in the case of sunflower oil the rate of formation of the cis-9, trans-11 CLA isomer was significantly higher after the different incubation times as compared to soybean oil. Much lower amounts of CLA were formed when fish oil was incubated in the rumen. The level of cis-9, trans-11 isomer produced during these treatments was 10% less than the amount obtained with the other two oils of vegetable origin. Besides the cis-9, trans-11isomer, trans-10, cis-12 CLA could also be detected during the incubation of the different oils in the rumen. However, the level of this isomer was low and did not show consistent differences among the treatments. The results of this experiment indicate that the fatty acid composition of the oils and the duration of incubation collectively determine the amount of CLA produced in the first compartment of the forestomach of ruminants.
Numerous different agroecosystems (alfalfa, apple, cereals, oilseed rape, maize, sunflower fields and plantations, a pasture and a compost hill) were investigated on the basis of the soil dwelling mites in two parts of Hungary. Twenty-three species of Mesostigmata, 13 Oribatida, one Astigmata and one Prostigmata are listed from these specific ecosystems, of which nine species, Alliphis halleri (G. and R. Canestrini, 1881); Antennoseius avius Karg, 1976; Antennoseius pannonicus Willmann, 1951; Arctoseius eremitus (Berlese, 1918); Cheiroseius bryophilus Karg, 1969; Leioseius insignis (Hirschmann, 1963); Oppiella loksai (Schalk, 1966); Punctodendrolaelaps fimetarius (Karg, 1965); Rhodacarellus perspicuus Halaśkova, 1958 are new to the Hungarian fauna.
Oil smears /2–10 mg/ on a filter paper were directly brominated by bromine vapor, and the quantity of Br reacted with the lipid was determined by instrumental neutron activation analysis. The iodine value for commercially available almond oil, sunflower oil, peanut oil, soy oil and sesame oil were determined by the proposed method. The relative standard deviation associated with the measurements was less than 3%. No significant difference was observed between the iodine values determined by the proposed method and that determined by one of the officially approved methods. The proposed method possesses the advantages of shortening reaction time and applicability to small sample size.
Authors:Sanjiv Arora, Rajeev Bagoria, and Mahender Kumar
Alpha-tocopherol (vitamin E) is the most widely used antioxidant for edible oils. The present investigation presents its effect
on the thermal degradation behavior of edible oils (sunflower, soybean, and their blend) through the use of dynamic thermogravimetry.
The study is based on the comparison of activation energies of decomposition process which were subsequently calculated using
preferred and reliable multiple-heating rate methods viz. Kissinger, Friedman, Ozawa–Flynn–Wall, and Coats–Redfern (modified).
It is concluded that the role of alpha-tocopherol as antioxidant at higher temperature is nearly accomplished.
Authors:Z. Ali, D. James, W. O'Hare, F. Rowell, and S. Scott
An electronic nose utilising an array of six-bulk acoustic wave polymer coated Piezoelectric Quartz (PZQ) sensors has been developed. The nose was presented with 346 samples of fresh edible oil headspace volatiles, generated at 45°C. Extra virgin olive (EVO), Non-virgin olive oil (OI) and Sunflower oil (SFO), were used over a period of 30 days. The sensor responses were then analysed producing an architecture for the Radial Basis Function Artificial Neural Network (RBF). It was found that the RBF results were excellent, giving classifications of above 99% for the vegetable oil test samples.
This work presents a study of the thermal decomposition of commercial vegetable oils and of some of their thermal properties
by termogravimetry (TG), derivative termogravimetry (DTG) and by differential thermal analysis (DTA). Canola, sunflower, corn,
olive and soybean oils were studied. A simultaneous SDT 2960 TG/DTA from TA Instruments was used, with a heating rate of 10
K min-1 from 30 to 700C. A flow of 100 mL min-1 of air as the purge gas was used in order to burnout the oils during analysis to estimate their heat of combustion. From
the extrapolated decomposition onset temperatures obtained from TG curves, it can be seen that corn oil presents the highest
thermal stability (306C), followed by the sunflower one (304C). Olive oil presents the lowest one (288C). The heat of combustion
of each oil was estimated from DTA curves, showing the highest value for the olive oil. Except for corn oil, which presents
a significantly different thermal decomposition behavior than the other oils, a perfect linear correlation is observed, with
negative slope, between the heat of combustion of an oil and its respective extrapolated onset temperature of decomposition
Authors:A. Kisbenedek, Sz. Szabo, E. Polyak, Z. Breitenbach, A. Bona, L. Mark, and M. Figler
Oilseeds are very popular edibles that are often used to enhance the fibre content of baked goods, and specific types are used for preserving and seasoning. Polyphenol-related researches have been receiving growing attention in the last 20 years, especially the ones concentrating on stilbenoids. In previous studies, resveratrol concentrations have been determined from oilseeds such as peanut.The aim of our research was to define the composition of oilseeds with a focus on the bioactive compounds, more specifically the resveratrol.Research took place in 2010–2011 at the University of Pécs, Medical School, using non-random, convenience sampling. Oilseeds studied in the research were: sunflower seed, roasted peanut, un-roasted peanut, sesame seed, pumpkin seed, almond, linseed, bio white mustard seed, bio black mustard seed, mustard seed of foreign provenance, and wild black mustard seed. All of these oilseeds can be purchased from trade. Samples used in the research were obtained from the producers and collectors. High Performance Liquid Chromatography (HPLC) was used for the measurements.Summarising our results, it can be stated that each type of oilseed analysed in our research can be regarded as good sources of resveratrol. The highest level of resveratrol was detected in the sunflower seeds (0.00398±0.0001 mg g−1), almonds (0.00176±0.00021 mg g−1), roasted peanut (0.00206±0.00013 mg g−1), and wild black mustard seeds (0.0023±0.0007 mg g−1).