scholarly journals Impact of the seed storage time on the quality of cold-pressed sunflower oil

2014 ◽  
pp. 67-77 ◽  
Author(s):  
Tamara Premovic ◽  
Sanja Dimic ◽  
Olga Radocaj ◽  
Etelka Dimic

The objective of this study was to investigate the impact of seed storage time on the quality of cold-pressed sunflower oil. The quality and oxidative stability of oil was determined in samples of domestic varieties of sunflower hybrid, linoleic type seeds, obtained from fresh seeds and from seeds stored in silo cell for 6 and 12 months at temperature below 30oC and in good ventilation conditions. It was found that the longer storage time of seeds had a negative impact on many quality aspects of the oil, such as flavor, odor and aroma, primarily on the sensory profile. Chemical characteristics and oxidative stability of oil were also influenced by the storage time, which was confirmed by increased values of the acid value (AV) and peroxide value (PV) of the oil samples. Fresh seed oil had an AV of 0.49?0.01 mgKOH/g, while oils that were obtained from one-year old seeds had an AV of 1.95?0.02 mgKOH/g. Content of the primary oxidation products in the oil obtained by cold-pressing of the fresh seeds was 1.73?0.02 mmol/kg (measured as PV), and 2.22?0.07 mmol/kg in that from the seeds stored for 12 months. The anisidine value for the oil obtained from the seeds stored for 12 months was 0.86?0.04 (100A1% 350nm).

2015 ◽  
Vol 69 (2) ◽  
pp. 175-184 ◽  
Author(s):  
Etelka Dimic ◽  
Tamara Premovic ◽  
Aleksandar Takaci ◽  
Vesna Vujasinovic ◽  
Olgica Radocaj ◽  
...  

The objective of this study was to investigate the impact of the storage time, content of the husk and impurities in the seed mass on the oxidative stability of the cold pressed sunflower oil. The oxidative stability of oil was analyzed by the RSM (Response Surface Methodology), where the response value (output) of the model was the content of oxidation products measured via specific absorbance at 232 nm for conjugated dienes and 270 nm for conjugated trienes. Analyses were performed on the fresh oil samples and oil samples tempered under the Schaal-Oven?s test conditions (96 h at 63?2?C). It was concluded that the seed storage time had significant impact on the primary (A1%232nm) and secondary (A1%270nm) oil oxidation products, both before (b1-p<0,001; b1-p=0,021) and after (b1-p=0,048; b1-p=0,033) the heating of oil. The content of impurities and husks in the seeds used for pressing also had an influence of the conjugated dienes and trienes contents in both, fresh and heated oil samples. However, their impact was not statistically significant. Interaction of seed storage time, the content of impurities and husks also exert some effect on the values of these quality parameters in the fresh oil as well as in the oil after the heat treatment, even though their influence is not significant. The obtained results have shown that the cold pressed sunflower oil had a good oxidative stability at temperatures up to 63?2?C.


2012 ◽  
Vol 30 (No. 4) ◽  
pp. 343-350 ◽  
Author(s):  
E. Dimić ◽  
T. Premović ◽  
A. Takači

The effects of different contents of impurities and seed hulls in the raw material on the sensory characteristics, chemical quality, and oxidative stability of sunflower oil prepared by the procedure of cold pressing on a screw press were investigated. It was found that the presence of impurities (up to 10%) and hulls (up to 32%) had an adverse effect on the sensory and chemical characteristics of the oil. The adverse influence on the oils colour was also evidenced from the results of measuring their transparency, which ranged from 14.75% to 43.60%. The presence of impurities and seed hulls caused also a decrease in the oxidative stability of oils, as the values of the induction period ranged from 3.63 h to 4.63 h, while the Totox values were in the range from 2.25 to 5.87. &nbsp;


2017 ◽  
Vol 71 (2) ◽  
pp. 175-182
Author(s):  
Ranko Romanic ◽  
Snezana Kravic

In this paper the oxidative stability of cold pressed sunflower oil of high-oleic type was investigated, using Schaal?Oven test at elevated temperature (63?2?C). At the same time samples of linoleic type oils, cold pressed and refined, were tested. The extent of oxidative changes was analyzed regarding the content of primary and secondary oxidation products during the period of 14 days. To especially expressed increase in oxidative values, with very high values of the coefficient of determination occurred in samples of linoleic type of oils, cold pressed and refined, whereas these changes were much less observed in the sample of cold pressed sunflower oil of high-oleic type (R2 ? 0.99). The cold pressed oils of high-oleic and linoleic type, as well of refined sunflower oil of linoleic type were measured and the content of conjugated dienes and conjugated trienes. In the period of 14 days, the lowest increase in oxidative value and the lowest degree of conjugation into the conjugated diene and triene were determined in cold pressed sunflower oil of high-oleic type, indicating a significantly better oxidative stability of this type of oil compared to linoleic types.


Author(s):  
Dariusz AMPUŁA

A statistical analysis of multiyear laboratory test results of artillery tracers number 8 is presented in this article. This analysis was aimed at testing the impact of a natural ageing process on quality indicators during the long-time storage of these tracers. The influence of storage time on taking a diagnostic decision, relating to quality of lots after the conducted laboratory tests and on different classes of inconsistencies that occurred during these tests, was analysed. A detailed analysis of the impact of the storage time on diagnostic shooting decisions taken was also presented. The conducted statistical analysis suggests an assumption, that it is possible to change an evaluation module in the previous test’s methodology. Modification of this evaluation module will not negatively impact on the quality of further diagnostic tests. It will not negatively impact on correct evaluation of the prediction process of the tested elements of ammunition such as artillery tracers. The statistical analysis, carried out in the article, may have a significant impact on the modification of test methodology of the artillery tracers.


2021 ◽  
Vol 38 (1) ◽  
pp. 144-157
Author(s):  
Thaísa De Oliveira Silveira ◽  
Madelon Rodrigues Braz ◽  
Gilmara Pires de Moura Palermo ◽  
Tiago Böer Breier

Seeds of native forest species for food and seedling production have a growing demand that impacts the need for studies involving seed storage in order to maintain good levels of germination quality. Thus, scientific analyzes that explore the physiological potential of the seeds of these species are necessary, especially for the pink pepper (Schinus terebinthifolia Raddi.), a species used as an alternative source of income for traditional communities and which has been arousing interest due to the consumption of its fruits as a condiment in the national and international market. This work aimed to assess the physiological quality of pink pepper seeds according to the storage period and seed size. The seeds came from a rural settlement, a pioneer in the extraction of pink pepper, in the state of Rio de Janeiro, Brazil. The seeds were evaluated for moisture content, germination, first count, length and dry weight of the germinated seedlings, during the period of time that they remained stored and the size of the seeds. The results allowed to conclude that: i) the germinative percentage of the stored pink pepper seeds decreased over the months; ii) the moisture content of the seeds decreased over the months evaluated iii) the different sizes of seeds did not show differences in germination and storage time and iv) values of length and dry weight of the seedlings did not differ according to the period of storage.


Molecules ◽  
2020 ◽  
Vol 25 (23) ◽  
pp. 5688
Author(s):  
Cristina-Ramona Metzner Ungureanu ◽  
Mariana-Atena Poiana ◽  
Ileana Cocan ◽  
Andreea Ioana Lupitu ◽  
Ersilia Alexa ◽  
...  

This research was conducted in order to establish the effectiveness of two freeze-dried extracts obtained from blueberry processing byproducts resulting from juice manufacturing compared to butylated hydroxytoluene (BHT) in delaying the lipid oxidation of sunflower oil subjected to high-temperature convective heating at 180 °C up to 12 h under simulated frying conditions. The fruits were harvested from spontaneous flora of two regions of Romania, Arieseni (Alba County) and Paltinis (Sibiu County) and the blueberry byproducts extracts (BBE) were noted according to the origin place as ABBE and PBBE. The progress of lipid thermo-oxidation was investigated in terms of peroxide value (PV), p-anisidine value (p-AV), the response of TBA-malondialdehyde interactions assessed by thiobarbituric acid (TBA) method, the total oxidation (TOTOX) value and inhibition of oil oxidation (IO). The recorded data highlighted that BBE exhibit a high inhibitory response on lipid thermo-oxidation. The inhibitory effect was concentration-dependent, thus, the degree of lipid oxidation was in reverse related to the BBE dose. The exposure of the oil samples supplemented with 800 ppm BBE (ABBE, PBBE) to a high-temperature heating for 12 h led to a significant decrease of the assessed indices compared to additives-free sunflower oil sample as follows: PV (46%; 45%), p-AV (21%; 17%), TOTOX (27%; 24%), TBA value (25%; 11%). Regarding the impact of the origin on the potential of BBE to inhibit the lipid oxidative degradation, it was noted that ABBE derived from blueberries grown in a region with a milder climate with moderate precipitations and higher temperatures showed a stronger inhibitory effect on lipid thermo-oxidation than PBBE. A moderate level of 500 ppm BBE inhibited the lipid oxidation similar to 200 ppm BHT. The reported results reveal that BBE represent efficient natural antioxidants that could be successfully applied to improve the thermo-oxidative stability of sunflower oil used in various high-temperature food applications.


2021 ◽  
Vol 22 (2) ◽  
pp. 332-343
Author(s):  
Ahmed Raza Sidhu ◽  
saba Naz ◽  
Sarfaraz Ahmed Mahesar ◽  
Abdul Rauf Khaskheli

The objective of our study is to monitor the oxidative stability of different cultivars of almonds (Australian, American and Iranian) kernels/oil during the 12th month of storage at room temperature. Several physicochemical parameters free fatty acids (FFA), peroxide value (PV), panisidine value (p-AV), total oxidation value (TOTOX), Fourier transforms infrared spectrophotometer (FT-IR) and Gas chromatography Mass spectrometry (GC-MS) were used to check the oxidative stability of almond kernel. According to the results, effects of room temperature in the early stages of oxidation, primary oxidation products remained stable, whereas secondary oxidation product levels continued to rise in the later stages. In general, FFA increased with increasing storage time, the range was observed (0.21-0.97 %), PV (1.31-16.23 meqO2/kg), p-AV (2.21-19.35), TOTOX (4.83-15.81), respectively. During storage at room temperature for up to 12th months, there was no significant shifting of the spectral band in the FT-IR study. The most bounteous fatty acid in the almond oil range was observed oleic acid C18:0 (71.01-79.56 %) followed by linoleic acid C18:2 (13.13–20.65 %), palmitic acid C16:0 (4.86-5.67 %), stearic acid C18:0 (1.20-3.81 %), and palmitoleic acid C16:1(0.21-0.47 %) in all three samples during storage. These results suggest that almond oil during the 12th month of storage keeps its good chemical properties.


Author(s):  
Malikhatul Marati ◽  
Muhammad Ali Faisal ◽  
Ikhsan Dwi Anggoro ◽  
Saiful Anwar

This study aims to determine the effect of e-service quality on e- loyalty with e-satisfaction as an intervening variable for muslim travellers. The population are Traveloka users in Java. Purposive random sampling are used. The sample was obtained from 170 respondents by online collecting data questionnaire. SPSS 21.0 program are used to data analyze. The analytical tool were Multiple Regression and Path Analysis. The results showed that: e-service quality aspects of reliability, tangible, and empathy had a positive and significant effect on e-satisfaction. E- satisfaction and E-Service have a positive and significant impact on e- loyalty. E-satisfaction can mediate the impact of reliability, tangible, and empathy on e-loyalty, while responsiveness and assurance do not mediate the effect of e-satisfaction on e-loyalty The results of this study can theoretically strengthen the existing theory that e-satisfaction can mediate the effect of reliability, tangible and empathy on e-loyalty, while responsiveness and assurance do not mediate the impact of e-satisfaction on e-loyalty. The practical implications in this study are used as input for platform provider to improve the quality of services provided by platform provider to muslim travelers.


2021 ◽  
Author(s):  
Khaldi Zahran ◽  
Nafti Mounir ◽  
Jilani Tabarek

Abstract This study was planned to investigate the raw milk characteristics and quality aspects and to evaluate the impact of nongenetic factors on physicochemical composition and microbial quality of milk from local Maghrebi camels (Camelus dromedarius) kept under a traditional system in oasis areas, southern west, Tunisia. Forty-nine individual milk samples were collected from lactating Negga over two periods of the year (winter and summer). Animals belonging to private flocks were between 5 and 17.5 years of age, with parity numbers ranging from first to sixth. Samples were analyzed for physical parameters, chemical composition, mineral concentrations, and microbiological features according to standard methods. The overall means of physical characteristics were 6.63 ± 0.22, 1030.63 ± 2.54, and 19.11 ± 4.08 for pH, density, and acidity, respectively. No significant association (P > 0.05) between physical characteristics and nongenetic factors has been observed. The average results of chemical composition for dry matter, protein, fat, casein, lactose, ash, and casein/protein ratio were 115.24±15.67g/L, 30.98±6.40 g/L, 32.84±4.88 g/L, 22.77±4.27 g/L, 37.21±4.64 g/L, 6.87±1.59 g/L, and 0.74±0.06 g/L respectively. Season, parity, and age were confirmed to impinge significantly on chemical components, except for lactose. The maximum contents of total solids, protein, casein, and fat content were observed during winter. The third lactation was characterized with the highest content of total solids, protein, casein, and lactose; while the highest fat content was recorded in the second lactation. Lactose content was stable throughout all the studied age classes (P > 0.05), whereas the other chemical constituents, showed an obvious superiority in the age class of 7≤ age ≤ 9 years. Season, parity, and age of the animal exerted a significant effect on all minerals. The highest levels of Ca, P, and K were recorded in the winter (P<0.01) whereas Na showed an opposite pattern and was higher in the summer (P<0.01). All major minerals were higher in milk from multiparous than primiparous camels, with maximum concentrations at the fourth lactation. The uppermost levels of mineral concentrations were recorded in the age class of 7≤ age ≤ 9 years. The lowest ones were those of animals over 12 years old. The microbial analysis of raw milk which is affected by season, parity, and age showed higher overall contamination levels in all studied bacterial counts. The highest levels were observed in winter, among the multiparous and oldest Negga. The results highlighted the complete absence of the two dangerous pathogens Salmonella and CSR in all analyzed samples.


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