Analiza kvaliteta ulja sa različitih regija maslinarskog područja Libije

Olive oil is one of the oldest and best known edible oils, which is in category of unrefined vegetable oils produced in hugest quantities. Olive oil is distinguished from other oils by the various specific characteristics, so demand for olive oil is permanently in progress. Olives are grown in all regions of the world, where climate conditions are favorable for their growth. In some countries of North Africa production of olive oil is significant. In Libya olive is a primary oil culture and olive oil is produced by many individual producers in a traditional way of cold pressing or by centrifugation. The aim of this paper was to examine basic chemical and nutritive quality of virgin olive oil from five different regions in the north of Libya: Aboras, Be, Zwit, El Farok and Alati. Olives are processed by Rapanelli system (Italy, Foligno). Processing included cleaning and washing of olive fruits, crushing and malaxation after which the oil separated by centrifugation. It has been established that examined oil samples that originate from Libya have a good chemical and nutritive quality. Content of primary oxidation products varied from 0.96 mmol/kg (oil from the Zwit region) to 2.40 mmol/kg (oil from the Alati region). Content of free fatty acid varied in the range from 1.39 to 3.17 % of oleic acid. According to a high content of total phenolic compounds (121.2 mgGAE/kg of oil) and the highest antiradical activity (proportion of neutralized free DPPH radicals 70.72%) among examined oil samples, the oil sample from the Alati region distinguished itself, while the minimum content (64.9 mgGAE/kg of oil) of such extremely valuable nutrient, as well as the minimal antiradical activity (60.12% of neutralized free DPPH radicals) has been registered in the sample from the Zwit region.Maslinovo ulje danas je jedno od najstarijih i najpoznatijih jestivih ulja koje se u kategoriji nerafinisanih biljnih ulja proizvodi u najvećim količinama. Maslinovo ulje se posebno izdvaja od drugih ulja po raznim specifičnim atributima, te je potražnja za njim u stalnom porastu. Masline se gaje u svim regionima sveta gde su povoljni klimatski uslovi za njihov rast. U pojedinim zemljama na severu afričkog kontinenta takođe postoji značajna proizvodnja maslinovog ulja. Maslina je i u Libiji osnovna uljana kultura i veliki je broj individualnih proizvođača koji proizvode ulje na tradicionalan način procesom hladnog presovanja ili pomoću centrifuge. U okviru ovog rada ispitivan je osnovni hemijski i nutritivni kvalitet devičanskih maslinovih ulja poreklom iz pet različitih maslinarskih regiona na severnom području Libije: Aboras, Be, Zwit, El Farok i Alati. Plodovi maslina su prerađivani sistemom Rapanelli (Italy, Foligno). Prerada je obuhvatila čišćenje i pranje maslina, mlevenje i malaksaciju, nakon čega je ulje izdvojeno pomoću centrifuge. Ustanovljeno je da su ispitivani uzorci ulja poreklom iz Libije dobrog hemijskog i nutritivnog kvaliteta. Sadržaj primarnih produkata oksidacije kretao se od 0,96 mmol/kg (ulje sa područja Zwit) do 2,40 mmol/kg (ulje sa područja Alati). Sadržaj slobodnih masnih kiselina je varirao u opsegu od 1,39 do 3,17%. Po visokom sadržaju ukupnih fenolnih jedinjenja (121,2 mgGAE/kg ulja) i najvećoj antiradikalnoj aktivnosti (udeo neutralizovanih slobodnih DPPH radikala 70,72%) među ispitivanim uljima istakao se uzorak ulja sa područja Alati, dok je najmanji sadržaj ovih izuzetno vrednih nutrijenata (64,9 mgGAE/kg ulja), kao i najmanja antiradikalna aktivnost (60,12% neutralizovanih slobodnih DPPH radikala) zabeležena u uzorku sa područja Zwit

Parametri kvaliteta suncokretovog ulja i palminog oleina tokom višestrukog prženja

The refined sunflower and palm oils are used in the food industry for the production of fried potatoes. Literary data have shown that palm oil had less tendency to degradation than sunflower oil due to its fatty acid composition. However, palm olein is a palm oil fraction and therefore has a different composition of fatty acids. The aim of this study was to investigate the quality of the refined palm olein in relation to the refined linoleic type sunflower oil during the production of fried potatoes. The oil samples were used for multiple frying during the seven days (40 minutes per day at a temperature of 165o C). The peroxide value and free fatty acid content (acid value) were determined by standard analytical methods. The results showed that the peroxide value in sunflower oil and palm olein increased by 75.0% and 77.8%, while the acid value increased by 50.0% and 26.8%, respectively, in relation to their initial values in the fresh oil samples. Based on these results, it can be concluded that the palm olein was more suitable for frying. However, this finding cannot be reported with certainty because the quality of the oil depends on many more parameters, not only on those analysed in this paper.U prehrambenoj industriji se za proizvodnju prženog krompira koriste rafinisano suncokretovo i palmino ulje. Prema literaturnim podacima, palmino ulje ima manju sklonost ka degradacionim promenama u odnosu na suncokretovo ulje, zahvaljujući sastavu masnih kiselina. Međutim, palmin olein je frakcija palminog ulja i samim tim ima drugačiji sastav masnih kiselina. Cilj ovog rada bio je da se ispita kvalitet rafinisanog palminog oleina u odnosu na rafinisano suncokretovo ulje tokom proizvodnje prženog krompira. Uzorci ulja su korišćeni za višestruko prženje tokom sedam dana (po 40 minuta svakog dana, na temperaturi od 165o C). Peroksidni broj i sadržaj slobodnih masnih kiselina (kiselinski broj) određeni su standardnim analitičkim metodama. Rezultati su pokazali da se peroksidni broj u suncokretovom ulju i palminom oleinu povećao 75,0% odnosno 77,8%, dok se kiselinski broj povećao 50,0% odnosno 26,8%, u odnosu na početne vrednosti u uzorcima svežeg ulja. Na osnovu ovih rezultata može se zaključiti da je palmin olein pogodniji za prženje. Međutim, ovaj zaključak se ne može navesti sa sigurnošću jer kvalitet ulja zavisi od mnogo više parametara, a ne samo od onih analiziranih u ovom radu

Sensory and some chemical characteristics of olive oils produced in Libya

Libya is one of the considerable olive oil producers in North Africa. The consumption of olive oil in this country is part of the cultural heritage and a large number of individual manufacturers produce oil applying the process of cold pressing. The aim of this work was to determine the sensory profile and some main chemical characteristics, as free fatty acids, peroxide value, total phenols content and induction period of virgin olive oils. Oil samples were extracted from a blend of three olive cultivars typical for Libya: Roghiani, Hammudi and Endori, harvested in five different regions of northern Libya in the crop year 2015. Obtained results have shown that investigated olive oil samples were characterized by different sensory profile and chemical characteristics, due to peculiar effect of harvest areas of olive fruit. On the basis of investigated attributes, some oils were of excellent quality, but other were under. The free fatty acid contents varied between 0.73% to 2.78 % of oleic acid, peroxide values ranged from 6.40 mml/kg to 13.65 mmol/kg and induction period from 4.89 h to 18.33 h. The content of total phenols, as especially important compound for health benefit of olive oil, was also significantly various, from 56.0 to 238.3 mg GAE/kg of oil. It can be concluded that the oil from Gharyan production region was quite different from the other Libyans' olive oils. This oil had the best sensory profile, basic chemical quality, oxidative stability and the highest phenolic content

Comparative review of the nutritional value of cold-pressed pumpkin (cucurbita pepo l.) Seed oil of different origins

The objective of this study was to investigate the nutritional value of seven samples of cold pressed pumpkin oil of different origins and influence of seed origin on the content of the most important bioactive components. Four samples of a pumpkin oil is obtained by cold pressing of the seeds of domestic and Austrian varieties, and three samples of cold pressed oils were obtained from the seeds of unknown origin, taken by free choice in the market. As indicators of the nutritional values are determined by the composition and content of fatty acids, tocopherols and sterols. In the composition of the fatty acid were oleic dominant (34.2 +/- 0.09-43.9 +/- 0.04%) and linolenic fatty acid (30.8 +/- 0.09-46.9 +/- 0.015%). This study confirmed that the oil pumpkin dominant beta+gamma-tocopherol, whose contents ranged from 34.65 +/- 0.03 to 44.59 +/- 0.69 mg/100 g. We determine the composition and content of Delta(7)-phytosterols, especially for specific oil pumpkins. It was detected five Delta(7)-sterols: spinasterol, Delta(7,22,25)-stigmastatrienol, Delta(7,25)-stigmastadienol, Delta(7)-stigmasterol and Delta(7)-avenasterol. Dominant content was Delta(7,22)-stigmastadienol or spinasterol with 39.98 to 50.31% of the total content of sterols

Supplementary data for the article: Čolić, S. D.; Bakić, I. V.; Dabić Zagorac, D. Č.; Natić, M. M.; Smailagić, A. T.; Pergal, M. V.; Pešić, M. B.; Milinčić, D. D.; Rabrenović, B. B.; Fotirić Akšić, M. M. Chemical Fingerprint and Kernel Quality Assessment in Different Grafting Combinations of Almond Under Stress Condition. Scientia Horticulturae 2021, 275, 109705. https://doi.org/10.1016/j.scienta.2020.109705

Supplementary material for: [https://doi.org/10.1016/j.scienta.2020.109705]Related to published version: [https://cherry.chem.bg.ac.rs/handle/123456789/4081

Tehnološke karakteristike i kvalitet semena slobodnooplodnih i hibridnih sorti uljane tikve

The technico-technological and chemical characteristics of seed of 8 free-fertilized and hybrid sorts of oil pumpkin seed with and without hull and two commercial samples of oil pumpkin were investigated. Liter mass and mass of 1000 grains were determined and the percentage of hull in seed samples with hull. The chemical composition was determined investigating the content of moisture, oil, proteins, mineral matter, fiber and total carbohydrates. Regarding the technico-technological characteristics, no significant differences between seeds of free-fertilized and F1 hybrids of oil pumpkih hull-less seed and seed with hull were found. The self-fertilized sorts and F1 hybrids of oil pumpkin, both hull-less and seed with hull, are characterized by high oil content, in the range of 43,27 to 54,78%, calculated on dry matter. The protein content was also high, from 34,97 to 36,61%, on dry matter.Ispitivane su tehničko-tehnološke i hemijske karakteristike semena 8 slobodnooplodnih i hibridnih sorti uljane tikve golice i sa ljuskom i dva komercijalna uzorka uljanih tikvi. Od tehničko-tehnoloških karakteristika semena određene su litarska masa, masa 1000 semena i određen je procenat ljuske kod uzoraka semena sa ljuskom. Hemijski sastav semena određen je ispitivanjem sadržaja vlage, ulja, proteina, mineralnih materija, celuloze i ukupnih ugljenih hidrata. U pogledu tehničko-tehnoloških karakteristika nisu postojale značajne razlike između semena slobodnooplodnih i F1 hibrida uljanih tikvi golica i sa ljuskom, kao ni komercijalnih uzoraka, što ukazuje da poreklo semena nije imalo uticaja na ove karakteristike. Samooplodne sorte i F1 hibridi uljanih tikvi sa semenom golica i semenom sa ljuskom, odlikovale su se visokim sadržajem ulja koji se kretao od 43,27do 54,78% računato na suvu materiju, a karakterističan je bio i visok sadržaj proteina koji se kretao od 34,97 do 36,61%, računato na suvu materiju

Chemical characterization of hull-less pumpkin seed oil press-cake

The utilization of agricultural waste products to produce food has recently received increased attention, not only to minimize waste disposal problems, but to help maximize potential resources and production of new and novel food products. The objective of this study was to characterize the pumpkin oil press-cake, a by-product of the pumpkin seed oil pressing process. The cakes were obtained by pressing the domestic variety of hull-less pumpkin seeds (Cucurbita pepo L.) "Olinka". Two pressing processes were applied: using a continual screw press in cold-pressed oil manufacturing and hydraulic press in the virgin pumpkin oil pressing process. In order to assess the suitability of this by-product, proximate analyses of the samples were conducted to determine the residual oil and water contents, as well as proteins, carbohydrates, crude fibers and ash using official methods of analysis. The residual oil was also analyzed in order to determine its nutritive quality. The obtained results showed that two kinds of oil press-cakes were significantly different in terms of oil and water contents. The press-cake obtained using a screw press had higher water content (8.30 ± 0.40%) and lower residual oil content (13.41 ± 1.48%), compared to the press-cake obtained using a hydraulic press (3.94 ± 0.65% water content and 18.18 ± 9.44% residual oil). In addition, the pumpkin press-cakes had a substantial amount of high quality proteins. The protein content of the press-cake obtained using a screw press was 67.09 ± 3.08 % d.m., while the protein content in the cake obtained using a hydraulic press was 59.20 ± 5.13% d.m. Results have also confirmed that the residual oil, regardless of the pressing method used, was of high quality, especially in terms of the high content of the essential omega-6 (linoleic fatty acid) and gamma tocopherols. The obtained results confirmed that both press-cakes can be used in different applications as value-added, functional ingredients for food manufacture

Nutritional value of the oil extracted from the pumpkin seed oil cake

Oil cake is a by-product which remains after the pressing of pumpkin seeds. Until recently, it was mainly used as animal fodder, but lately it has been increasingly used for nutritious food products or ingredients. As the cake retains a considerable portion of oil, the aim of this research was to determine the content of oil in the cakes obtained after pressing 7 samples of naked pumpkin seeds and 3 samples of husk pumpkin seeds, and the nutritional value of the residual oil. The content of oil varied from 11.0 to 16.0 % in dry matter. After that, in the next 24 hours, the oil left behind in the cake was extracted by hexane, at room temperature. The composition and content of fatty acids and the total content of tocopherols were determined. The dominant acids were oleic acid (37.1-43.9%) and linoleic acid (30.8-44.5%), an ω-6 fatty acid. There was also a small portion (0.1-0.3%) of linolenic acid, an ω-3 fatty acid. The total content of tocopherols was considerably high (28.7-64.5 mg/100g), with the γ-isomer being the dominant one (73.6-85.3% of the total content)

The influence of cutting thickness, shape and moisture content on oil absorption during potato frying [Uticaj debljine listova, oblika i sadržaja vlage krompira na apsorpciju ulja tokom prženja]

Potato chips and French fries are products which are often used in the human diet. The aim of this study was to investigate the influence of cutting thickness, shape and moisture content on palm olein uptake, as well as the quality of the palm olein during the production of fried potatoes. Blanching operation was conducted in water for 3 minutes at a temperature of 85oC, while the frying process was conducted in palm olein for 3 minutes at a temperature of 165oC. The peroxide value and free fatty acid content (% oleic acid) were determined by standard analytical methods. The oil content in samples was determined by the standard Soxhlet extraction (the reference method). The results showed that the potato chips had approximately four times more oil uptake compared to potato sticks. The oil content was significantly lower in blanched potato slices (by 43.3%) but significantly higher in blanched potato sticks (by 53.5%) compared to unblanched samples. The analyzed quality parameters of palm olein were within the allowable value range. Based on the results obtained in this study, it can be concluded that the thickness, surface area and moisture content of the potato had a significant effect on oil uptake

Thermo-mechanic and sensory properties of wheat and rye breads produced with varying concentration of the additive

The effects of different concentrations of the complex additive containing emulsifiers, oxido-reductive substances and enzymes, on the rheological conditions of dough, and on the sensory properties of three groups of bread were investigated. The best initial quality and the lowest degree of protein network weakening had the dough obtained from mixed wheat and rye flours. The best expected baking properties were shown by the white wheat flour due to the least damage of its starch. The use of the additive has an effect on the absorption of water and on the majority of C-values of all sorts of flour. The amount of additive had a significant effect on the sensory properties of wheat bread crumb texture. Also, storage duration significantly affected (p <0.01) the sensory properties of integral wheat bread aroma-taste and the weighted mean score. The interaction of these two factors had no significant effect on any of sensory properties of the investigated groups of bread