Free Fatty Acidity Research Articles

Regeneration of Used Frying Oils by Selected Metal–Organic Frameworks as Adsorbents

AbstractThe aim of this study was to utilize seven synthesized metal–organic frameworks (MOF) and three natural clays as adsorbents in regenerating used frying oil. First, surface and pore properties, and morphologies of the adsorbents were determined, and used frying oil was treated at 0.1% addition (w/w) level. Then, physicochemical properties, mineral, and fatty‐acid compositions of oil were analyzed. Finally, a recycling study was performed over five cycles with three selected adsorbents. Although there were only small improvements in oil color values, oil turbidity was significantly reduced with the adsorbents. Free fatty acidity values were reduced by 50.6% and 42.2% with Ti‐MOF and zeolitic‐MOF (ZIF‐8‐MOF) adsorbent treatments. Likewise, peroxide value reductions ranged from 43.6% with the Ti‐MOF to 18.1% with natural zeolite. Reductions in the total polar materials (TPM) were the highest (42.5%) with aluminum‐MOF (Al‐MOF) followed by the ZIF‐8‐MOF (40.4%). Contents of aluminum, zinc, phosphorous, chromium, magnesium, and potassium were measured in the control and adsorbent‐treated oil samples, and it was found that there was no leakage of minerals from the MOF into the oil, but rather some reductions due to adsorption. Furthermore, recycling studies with Ti‐MOF, Cr‐MOF, and sepiolite showed that the MOF can be used up to five times with only small activity losses compared with sepiolite. Overall, this study demonstrated the great potential of the MOF as adsorbents for frying oil regeneration, and pointed out that more research needed to design and synthesize new MOF structures for applying in the edible oil industry.

Effects of the storage of Turkish Gemlik olives under CO2 and N2 on the phenolic compounds and fatty acid compositions of olive oils

Because of the limited number and size of the oil extraction opportunities, olives are generally piled and stored at ambient temperatures for weeks before processing. Under these conditions biochemical changes could result a negative affect on the olive quality. The changes in the olive result poor stability in olive oil because of the oxidation and decomposition of bioactive compounds such as phenolic substances. Indeed, it is known that polyphenols are a large family of compounds found in plant tissues, which show strong antioxidant activity. The healthy characteristic of the phenolic compounds is associated to their radical scavenging activities. In this study, Gemlik olives cultivated from Osmaniye area were stored for 25 days at 5 °C under three different conditions (20 kPa CO2 atmosphere, 20 kPa N2 atmosphere and air). Olive oil was extracted following of 0, 5, 15 and 25 days of olive fruits storage. Qualtiy markers (free fatty acidity, peroxide value, K270 and K232) together with the phenolic compounds and fatty acid compositions of oils were determined. The physical properties of olives (flesh/pit ratio, average weight and fruit firmness) were well-preserved under CO2 and N2 atmospheres. The phenolics (tyrosol, syringic acid, vanilin, p-coumaric acid, oleuropein, cinnamic acid and luteolin) and fatty acids (palmitic, palmiteloic, heptadecanoic, heptadecenoic, stearic, oleic, linoleic, linolenic, arachidic, behenic, docosadienoic and lignoceric acids) composition were generally unchanged during storage. Oleuropein, the bitter principle of olives disapperead faster in the oils obtained through storage under N2 than other storage conditions.

Valorization of Capia Pepperseed Flour-II: Sensory Properties and Storage Stability of the New Spreadable Pastes

The aim of this study was to characterize spreadable products based on the utilization of capia pepperseed flour. Chocolate type including liquid chocolate, and molasses type including grape molasses were evaluated. The volatile aromatics compositions, sensory descriptions, consumer preferences and storage stabilities were studied. 24 volatile compounds in chocolate type and 17 volatile compounds in molasses type were quantified. 1,2,3-propanetriol, ethyl acetate and acetic acid in chocolate type, and acetic acid and methyl acetate in molasses type were dominant in concentrations. Volatiles with aroma descriptions of fruity, ethereal, nutty, buttery, cocoa, almond, green, fatty, caramel, vegetable and similar were quantified. The panel sensorially defined both products with 17 definition terms. Significant differences for brownness, nutty, raw vegetable, bitterness, chocolate/caramel, consistency, spreadability, and refreshment were determined, and thought to be caused from the main ingredients used. Consumer hedonic scores were generally higher for chocolate type, but both need improvements. Oil separation and water activity have not changed during the storage, while some color differences and microstructural changes occurred. Furthermore, free fatty acidity and peroxide value was not increased significantly and lower than 1.8% and 2.5 meqO2/kg, respectively. Overall, these new pastes could found some market value.

Temperature-Controlled Pulsed Light Treatment: Impact on Aflatoxin Level and Quality Parameters of Peanut Oil

Peanuts are an economically significant crop that is commonly used for edible oil production; however, they are prone to contamination by aflatoxin (AFT)-producing fungi. Common methods to treat edible oils for AFTs often utilize high temperatures (> 100 °C) to thermally degrade the toxins. However, high temperatures often negatively impact product quality. In this study, pulsed light (PL) was assessed as a possible method to degrade AFTs in peanut oil. A pilot-scale PL applicator was used to treat 5-mL samples of peanut oil of 10 mm thick. Samples were treated for 1 to 10 min with or without temperature reduction (TR). The sample containers were placed in an ice water bath to mitigate increases in oil temperatures for the TR samples. The physical, color, and chemical quality parameters (peroxide value, free fatty acid, acidity value, and oxidative stability index (OSI)) of the oil were assessed in comparison to controls. Results show that significant AFT destruction was achieved using PL. There was a significant difference between reduction achieved when TR was employed, likely due to the combined effect of photochemical and thermal treatment. TR samples treated for 400 s experienced an AFT reduction of 48.4%, while those treated 600 and 800 s achieved 55.6 and 78%, respectively. The samples treated with TR showed lower quality degradation when compared to peanut oil samples treated without TR for equivalent treatment times. Using TR, PL resulted in a significant reduction of AFT, without losses in quality typically associated with thermal methods. At industrial scale, PL may offer an economical treatment of AFT-contaminated oil.

Elaboración de Papas (Solanum tuberosum L.) Pre-Fritas, Congeladas y Saborizadas con Albahaca

El presente trabajo de investigación fue propuesto para elaborar papas prefritas y aplicar tratamientos de sabor con la adición de albahaca deshidrataba con el fin de mejorar la calidad sensorial y que se encuentre dentro del rango microbiológico permitido. Mediante un análisis organoléptico ejecutado por 30 panelistas, se logró determinar el mejor tratamiento en cuanto a olor, sabor, sabor residual, crujencia y color, teniendo como resultado el tratamiento 1 a 92°C, con una concentración de saborizado de 0.25% de albahaca deshidratada.
 Los resultados fueron analizados estadísticamente, el tratamiento 1 fue el más aceptado con un “me gusta mucho” en olor con un 63%, en sabor con un 43%, en sabor residual con un 70%, en crujencia con un 67% y en color con un 77% de aceptabilidad, lo cual lo pone en gran ventaja de los demás.
 Los resultados de los análisis físico-químicos y microbiológicos del tratamiento 1 fueron de 73,21 de humedad, 1,25 de acidez (acidez grasos libres), negativo para rancidez y 2x10¹ para levaduras y mohos; resultando dentro del rango de la normativa de referencia CODEX STAN 114 y B.O. del E-NUM.284.

LABORATORY AND FIELD STUDIES FOR EVALUATION OF SOME FRESH AND USED PLANT OILS ON THE GLASSY CLOVER SNAIL, MONACHA CARTUSIANA (MÜLLER)

recycling waste especially used frying oils is considered healthy and eco-friendly procedure. Considering as novel technique, molluscicidal activities were evaluated for two waste frying oils of sunflower and soybean baits against the glassy clover snail, Monarch cartesian (Muller) under laboratory and field conditions. Fresh oils of both were also tested. A promising result indicated that used frying oils of both sunflower and soybean exhibited potent mortality percentages after three weeks with 35 % concentration under laboratory conditions, where juvenile mortality for both used oils was 100 %, while adult mortality were 66.67, and 73.33 %, respectively. The lowest hatching % of M. cartesian was 41.98 for fresh soybean oil followed by 52.33, 57.48 and 60.78 % for used frying soybean oil, fresh and used sunflower oils, respectively. Similarly, field investigations estimated the residual effect of used frying sunflower and soybean oils on reduction percentages after three weeks were 55.32 & 57.39%, respectively with a concentration of 35 %. Compared to control, reductions in activities of amylase, invertase and trehalase enzymes in adults of M. cartesian treated with used frying soybean oil were recorded. In addition, physicochemical parameters (free fatty acids, acidity % and peroxide value) of fresh and used frying oil were measured.

Some chemical and microbiological properties of the butter and the butter oil produced from the same raw material

In this study, it was aimed to determine various characteristics of butter samples obtained from Van market and butter oil produced from these butters. Fat, acidity value, water activity (aw), peroxide value (PV), lipolysis (ADV), cholesterol, total fatty acid, free fatty acid compositions and conjugated linoleic acid determinations were made in butter and butter oil samples. Minimum and maximum values of the butter and butter oil samples respectively for free fatty acids, cholesterol, aw, peroxide and acidity values were determined as; 2415–27640 and 2026–14666 (mg/kg), 258–334 and 214–262 (mg/100 g fat), 0.96–1.00 and 0.48–0.82, 1.2–7.4 and 4.3–10.5 (meqO2/kg fat), and 0.2–2.2 and 0.05–1.7 (mL/100 g) respectively. Conjugated linoleic acid content of butter and butter oil varied from 0.5 to 1.7 and from 0.2 to 0.9 (g/100 g in total fatty acids) respectively. In general yeast–mould, lipolytic bacteria and lactic acid bacteria counts of butter oil were lower than butter. A positive correlation between aw and yeast–mould, lipolytic bacteria and lactic acid bacteria counts and among total free fatty acids contents, acidity values and ADV was observed.

Cold pressed versus refined winterized corn oils: quality, composition and aroma

The aims of this study were to characterize and compare cold pressed and fully refined winterized corn oils. Free fatty acidity (FFA), peroxide (PV) and p-anisidin (p-AV) values, saponification number, total carotenoid and phenolic contents of cold pressed corn oils were higher than that of the refined winterized corn oils. Linoleic and oleic acids (approximately 53-54% and 30-31%, respectively) were detected as the major fatty acids in both oil samples. Fifteen different sterols with a majority of β-sitosterol, campesterol, and stigmasterol were quantified in both oil samples. Although phenolic compounds were not quantified in the refined winterized oil samples, some flavonoids (hesperidin, rutin) and phenolic acids (gallic, syringic, rosmaniric and trans-ferulic) were detected in the cold pressed oil samples. This study concludes that cold pressed corn oils could be superior in terms of bioactive compounds but still need some quality improvements for sensory attributes.

Optimisation of Microwave-Assisted Extraction of Pomegranate (Punica granatum L.) Seed Oil and Evaluation of Its Physicochemical and Bioactive Properties.

Pomegranate seed oil was extracted in a closed-vessel high-pressure microwave system. The characteristics of the obtained oil, such as fatty acid composition, free fatty acidity, total phenolic content, antioxidant activity and colour, were compared to those of the oil obtained by cold solvent extraction. Response surface methodology was applied to optimise extraction conditions: power (176-300 W), time (5-20 min), particle size (d=0.125-0.800 mm) and solvent to sample ratio (2:1, 6:1 and 10:1, by mass). The predicted highest extraction yield (35.19%) was obtained using microwave power of 220 W, particle size in the range of d=0.125-0.450 mm and solvent-to-sample ratio of 10:1 (by mass) in 5 min extraction time. Microwave-assisted solvent extraction (MASE) resulted in higher extraction yield than that of Soxhlet (34.70% in 8 h) or cold (17.50% in 8 h) extraction. The dominant fatty acid of pomegranate seed oil was punicic acid (86%) irrespective of the extraction method. Oil obtained by MASE had better physicochemical properties, total phenolic content and antioxidant activity than the oil obtained by cold solvent extraction.

Rapid Methods for Frying Oil Quality Determination: Evaluation with Respect to Legislation Criteria

AbstractThis work focuses on the evaluation of commercially available rapid methods for determining frying oil quality. Five rapid methods differing in principle were selected: FOM320 (Ebro), PCT120 (3M), LRSM (3M), Fritest (Merck) and Viscofrit (Viscofrit). The performance of the methods was examined by use of 184 oil samples produced by controlled frying experiments. Twelve series of frying experiments (45 batches each) were performed in which the oil type (palm, sunflower and olive) and the food type (potatoes, zucchini and minced beef meat) varied. Control thermal oxidation experiments with the same oil types were also performed. Results of the rapid methods were compared to results of analytical methods determining legislation criteria. Namely, the total polar compounds and total polymer compounds were determined using High Pressure Size Exclusion Chromatography with and without prior separation of the polar fraction. Furthermore, determination of the free fatty acid concentration, acidity, viscosity and level of oxidation of the oils using UV spectroscopy were carried out. Principal component analysis and linear regression analysis were used in order to assess the obtained results. Comparison of the results of the rapid methods with the analytical ones showed differences in most examined cases. For many of the examined rapid methods the agreement of the results versus those of analytical methods depended on the food‐oil combination used in the frying experiments.

Quality characteristics and antioxidant properties of Turkish monovarietal olive oils regarding stages of olive ripening

The aim of this study was to discriminate the extra virgin olive oils (EVOO) based on quality characteristics, chemical composition and antioxidant activity according to ripening stages of olives. Two different olive varieties (Memecik and Gemlik) were obtained at different stages of ripening based on skin color (green, purple and black). Quality properties of olive oils; free fatty acidity, peroxide value, K232 and K270, purity properties; fatty acid and triacylglycerol (TAG) composition and antioxidant compounds like total phenol, carotenoid and chlorophyll content and antioxidant activity (oxidative stability, ABTS radical scavenging activity) analyses were performed. Higher amount of oleic, linoleic and palmitic acids were observed in olive oils. Oleic acid amount of olive oils decreased, linoleic acid increased with ripening. The most abundant TAG of olive oils were ECN 48, OOO, SLO+POO, ECN 46 and LOO/PLO. Olive oils were clearly classified by principal component analysis based on fatty acid and TAG composition.

Investigation of physicochemical and sensorial quality of a type of traditional meat product: Bez sucuk

In this research, the effects of different meat:fat ratios and storage periods on physicochemical and sensorial properties of a type of traditional meat product named as bez sucuks were investigated. For this purpose, three groups of bez sucuk were produced and named as BS10, BS20 and BS30 with the meat:fat ratios of 90:10, 80:20 and 70:30, respectively. Physicochemical and sensorial properties of samples were analyzed during processing and storage periods. Significant decreases in pH and water activity values, and increases in titratable acidity, free fatty acidity, thiobarbituric acid and peroxide values were observed at the end of the ripening stage. The results showed that proximate composition (except hydroxyproline content of BS10 and BS20) and pH values of all sucuk groups were in accordance with the food legislation and the sucuk standard. The results of sensory evaluation showed that BS10 and BS20 had the highest overall acceptance scores in comparison with BS30. According to the data, it is possible to produce bez sucuks named as BS10 and BS20 with a shelf life of approximately six months.

Chemical characterization of the lipid fractions of pumpkin seeds

Purpose– This paper aims to characterize the pumpkin (Cucurbita sp) seed oil from the varieties Nova Caravela, Mini Paulista, Menina Brasileira (Cucurbita moschata) and Moranga de Mesa (Cucurbita maxima) as to their physicochemical properties, vitamins and fatty acid and triacylglycerols profiles.Design/methodology/approach– The oils were extracted from oilseeds by the Bligh and Dyer (1959) method, and chemical characterization was performed by using standard methods for oils and fats. The vitamin A and E content, fatty acid profile and triacylglycerols profile also were determined.Findings– About the chemical properties, the oils showed values within the range for edible vegetable oils. The oil from variety Nova Caravela stood out for presenting better quality, as it showed lower values of free fatty acids, acidity and peroxides. However, it was found that the Moranga de Mesa oil was the most unsaturated, due to the high refractive and iodine index, and was also reported to have lower oxidative stability. Among the unsaturated fatty acids, ranging from 70 to 78 per cent of the total obtained, linoleic and oleic acids stood out, while among the saturated ones, palmitic and stearic did.Practical implications– These seeds are rich in high-quality lipids; therefore, their use could help to reduce the amount of waste produced in the industries, and consequently reduce environmental contamination. This study showed that the seeds could be used as a raw material for oil extraction, and also could be used for developing functional foods instead of being discarded.Originality/value– This study provides valuable information about the quality and fatty acid contents of pumpkin seed oils consumed in Brazil.

Properties and stability of deep-fat fried chickpea products

The aims of this study were to develop new snack foods prepared from deep frying whole chickpeas and evaluating the properties and storage stability of the new products. The most remarkable results found were: moisture content (3.48–9.19%), water activity (0.1833–0.5936), hardness (3243–4056 g), L (42.01–65.79), a* (10.56–19.24), b* (30.80–42.20), free fatty acidity (0.2195–0.3467%), pero xide value (3.167–5.25 meq O 2 ·kg −1 ), total phenolic (22.34–37.34 mgGA·100g −1 chickpea), antioxidant capacity (6.53–31.61 mmol Trolox·100g−1 chickpea), absorbed fat (13.46–13.92%), and caloric value (453.17–488.49 kcal·100g −1 chickpea). Hexanal, 2,5-dimethylpyrazine, nonanal, benzaldehyde, p -cymene, and carvacrol were the major volatile compounds determined. The color, hardness, moisture content, water activity, free fatty acids, and peroxide value of the products were monitored for three months at room temperature. Consumer acceptance tests were conducted to reveal the changes which occurred during the storage period. All the products developed and evaluated in this study show potential in the market and industry, with the plain type being the preferred product.

Antioxidant Active Packaging with Soy Edible Films and Oregano or Thyme Essential Oils for Oxidative Stability of Ground Beef Patties

AbstractThe effectiveness of soy‐based edible films (EF) incorporated with essential oils (EO) from oregano (OR, Oreganum heracleoticum L.) or thyme (TH, Thymus vulgaris L.) applied on oxidative stability of ground beef patties (GBP) was investigated at 4C for 12 days. Higher antioxidant activity by OR than TH EO was determined with a 2,2'‐diphenyl‐2‐picrylhydrazyl radical‐scavenging assay. Induction time of oxidation measured with the Rancimat test in lipids of GBP was extended with the addition of EOs to EFs. Lower peroxide and free fatty acidity (P < 0.05) values were determined with OR‐EF or TH‐EF, particularly at later stages of storage. Incorporation of EO from OR or TH into the EFs resulted in reduced, but acceptable, redness (a*) values (P < 0.05) in ground beef. This study suggests that the addition of OR or TH EOs into EFs as an antioxidant active packaging is effective in retarding oxidative changes in meats.Practical ApplicationsOxidation reactions are among the most important factors responsible for loss of quality in meat products. Packaging using edible films (EFs) with the inclusion of natural plant extracts is becoming a promising active packaging approach to control oxidative changes in food products during storage. This study was focused on the inclusion of thyme or oregano essential oils (EOs) into EF formulation to control oxidative changes in ground beef patties. Results indicate that inclusion of EOs as antioxidants into soy‐based EFs offers great potential in industrial applications for controlling oxidative changes in the manufacture of natural meat products.

Effect of date (Phoenix dactylifera L.) seed extract on stability of olive oil.

In this study, the antioxidant effect of date (Phoenix dactylifera L., Arecaceae) seed extracts at different concentrations (0.5%, 1.0% and 1.5%) on the oxidative stability of olive oil at 60°C was determined. Butylated hydroxyanisole (BHA) was used as positive control in the experiment. All extracts exhibited antioxidant activity compared to BHA up to 21days. When antioxidant effect of extract concentrations were compared with BHA, the effect of 0.5% extract concentration was more remarkable for olive oil up to 21days. After 14days of assay, all of seed extracts was effective at 60°C in comparison with control. On the other hand, an important increase was observed in both the peroxide and free fatty acidity values during the experiment period. It concluded that date seed extract could be used as a oxidative inhibitor agent in oil and oil products.

Effects of Nut Proportion and Storage Temperature on Some Chemical Parameters of Pistachio Nut Cream

Pistachio nut cream is a new product that was produced by mixing powdered sugar, roasted pistachio nut, defatted powdered milk, lecithin, vanilla and margarine. Pistachio nut cream was stored at 4 and 20 °C in sealed jars. Nut creams were analyzed by chemical analysis such as peroxide values (meq kg -1 ), total and free fatty acidity (%), moisture content (%), pH, 2-tiobarbutric acid and browning indices. Sensory evaluations of the cream were examined according to the color, odour, texture, taste, aroma and feelings by the panelists. Samples containing 10% and 15% pistachio nut that were stored at 4 °C were better and more acceptable with respect to the chemical properties of pistachio nut cream compared to the nut cream samples that were stored at 20 °C. Pistachio nut is mainly grown in many regions of the world, such as Iran, USA, Turkey, Greece, and Italy. It is consumed as salted, roasted and also used in dessert production such baklava and nut cream production in Turkey especially Gaziantep and Sanliurfa region as a main ingredient. Pistachio nut contains K, P and also various amounts of Ca, Mg, and Fe. Pistachio nut production is 35,000 tons annually in Turkey. The different cultivars of pistachios are grown in southeast region in our country such as Siirt, Ohadi, Halebi, Kirmizi, and Uzun. Pistachio nut contains 22% of protein, 55% of fat, 18% of carbohydrate and 5% of moisture (1). Fatty acid content of pistachio nut is 7%-10.5% of palmitic, 0.9%-2.5% of stearic, 54%-71% of oleic, 16%-35% of linoleic acid (2). Pistachio nut is being used in the production of baklava (special type of dessert in Turkey) and nut paste. Dried pistachios are highly susceptible to lipid oxidation because of high

Refining of buriti oil (Mauritia flexuosa) originated from the brazilian cerrado: physicochemical, thermal-oxidative and nutritional implications

The objective of this study was to compare the physicochemical, thermo-oxidative and nutritional characteristics of crude and refined buriti oil. Crude and refined oil samples were evaluated for viscosity, relative density, refraction, acidity, free fatty acids, peroxide and iodine, lipid oxidation degree by UV-Vis, thermogravimetry, calorimetry, in vitro antioxidant capacity, vitamin A content and fatty acids profile. The refining process decreased the free fatty acids percentage and acidity, peroxide and iodine indexes, with greater thermal-oxidative stability, which is critical for its use in cooking food. However, its antioxidant capacity, vitamin A and unsaturated fatty acids contents were reduced compared to crude oil. Therefore, it is suggested to optimize the refining process to minimize nutritional losses in buriti oil, which due to its characteristics, can be considered a functional food.

Chemical Stability of Extra‐Virgin Olive Oil Added with Oregano Essential Oil

Extra virgin olive oil is highly consumed and well known for its nutritional and health benefits. However, it is fatty food highly susceptible to lipid oxidation. The objective of this study was to evaluate the preserving effect of oregano (Origanum vulgare L. spp vulgare called "oregano compacto") essential oil on physical and chemical properties in extra virgin olive oil during storage. Oregano essential oil composition was analyzed by GC-MS. This essential oil was added into extra virgin olive oil at 0.05%. The samples were stored in 3 different conditions: darkness, light exposure, and temperature (60 °C). Chemical indicators of lipid oxidation (peroxide value, p-anisidine value, conjugated dienes, free fatty acidity, and carotenoid and chlorophyll contents) were measured. High content in carvomenthol (22.52%), terpinolene (19.77%), thymol (13.51%), and γ-terpinene (10.30%) were detected in oregano essential oil. Olive oil samples without oregano essential oil stored at 60 °C and exposure at artificial light had the highest peroxide values during storage. Higher p-anisidine and K232 values after day 7 of storage were detected in temperature, darkness, and light exposure treatments. Light treatment was the main factor that degraded chlorophyll causing loss of color. The highest chlorophyll content (3.87 mg/kg) was observed in olive oil with essential oil at the end of storage. In general, olive oil samples added with oregano essential oil had lower peroxide, conjugated dienes, and p-anisidine values and higher chlorophyll and carotenoid contents during storage. Oregano essential oil retards lipid oxidation process in olive oil prolonging its shelf life. Oregano essential oil was and is used with the purpose of flavoring and aromatizing food. This essential oil due to its composition has shown antioxidant activity. Synthetic antioxidants such as butylated hydroxytoluene (BHT) and butylated hydroxyanisole (BHA) are thought to be promoters of carcinogenesis. Extra virgin olive oil is widely consumed because of its nutritional benefits and sensory properties which are very important to be preserved in the product. In this study, the oregano essential oil showed remarkable antioxidant activity in olive oil. Therefore, this essential oil could be considered for the industry as natural antioxidant not only to be used in olive oil but also in other fatty food products to substitute synthetic ones.

Chemical composition of European squid and effects of different frozen storage temperatures on oxidative stability and fatty acid composition

The chemical composition of European squid (Loligo vulgaris) mantles and tentacles and the lipid oxidation during frozen storage at three different temperatures (-20º, -40º and -80°C) were investigated. The moisture, fat, protein and ash contents of tentacles were 80.72%, 1.44%, 16.16% and 1.63% while the same contents for mantle were 78.54%, 1.37%, 18.52% and 1.45% respectively. The initial free fatty acidity (FFA), peroxide (PV) and thiobarbituric acid reactive substances (TBARS) values of tentacles were 1.17%, 1.80meq O2/kg fat and 0.80mg malonaldehyde/kg respectively. The same results for mantles were 1.38%, 2.20meq O2/kg fat and 0.73mg malonaldehyde/kg respectively. PV and TBARS values increased with the storage time for all samples and higher storage temperature resulted with higher PV and TBARS values. The initial fatty acid compositions of L. vulgaris mantles were 29.95% saturated (SFAs), 9.95% monounsaturated (MUFAs) and 59.31% polyunsaturated fatty acids (PUFAs) and tentacles were 34.16% SFAs, 10.69% MUFAs and 55.15 PUFAs. SFAs content were increased but MUFAs and PUFAs contents were decreased during frozen storage of mantles and tentacles.