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Some physico-chemical characteristics of Iranian linseed oil (Linum usitatissimum) such as oil content (44.25%), refractive index (1.47), peroxide (7.21meqO2/Kg Oil), iodine (170.67gI2/100g Oil), acid (3.10mgNaOH/g Oil) and saponification (191.73mgKOH/g Oil) values and fatty acid profile (C16:0, C18:0, C18:1, C18:2, C18:3) were studied. For preservation of ω-3 ingredients, the linseed oil that containing 43.18% of ω-3 fatty acid, were kept in frozen condition (nitrogen atmosphere and -30 º C temperatures) and its peroxide value was determined after 0, 7, 30, 60 and 90 days. Statistical analysis showed significant difference (p<5%) average amount of peroxide value only in first 7 days of storage time and its increase (8.30%) conformed to international standard.

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The fatty acid composition and changes in silver carp fillet after flash frying, frozen storage and deep frying of was studied. For this purpose, fillets with edible coating and uncoated were tested. Fillets after flash frying for 30s, cooling, packaging and cooling were kept in freezer for three months, then deep fried.  Flash frying and final deep frying increased the amount of total fat in fillets. The fat content of samples (5.07% at day 0) changed to 9.52 ± 1.97 and 7.54 ± 2.80 % after flash frying and to 9.33 ± 0.70 and 9.39 ± 0.24 % after final deep frying in uncoated and coated samples, respectively. Moisture content decreased after frying and increased after 3 months frozen storage (P<0.05). Twenty six saturated and unsaturated fatty acids were detected in samples. N-3/n-6 ratio was 3.37 in control samples. This ratio was 0.82 and 0.65 for uncoated and coated samples, respectively after flash frying and decreased to 0.66 and 0.28 after final deep frying. Atherogenic index (AI) and thrombosis index (TI)  in day 90 after final deep frying in uncoated and coated treatments were 0.60, 0.53 and 0.57 and 0.69, respectively. 

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  According to increasing trend of the consumption of ready to use leafy vegetables, mainly impact of freezing on sensory attributes of the vegetables and necessity of determination of the best conditions for frozen storage of leafy vegetables, this research carried out for determination of the best frozen storage time and temperature of Allium ampeloprasum, Lepidium sativum and Stureia hortensis mixtures. This study was done at first for storage of ready to use and comminuted leafy vegetables entitled Ghormeh Sabzi mixture in -9, -12 and -18°C as well as 120, 150 and 180 days by explorer method. At second for frying of vegetables of Ghormeh Sabzi and comparison of sensory attributes of freezed vegetables at each month by experimental method. Sensory attributes all treatments containing color, taste and acceptability were evaluated and compared statistically. The results of freezing temperature in 3 times indicate that color in -18°C is the first rank (P≤0.05). Flavour has the first rank in -18°C in 120 and 150 days but flavour in 180 days in -12°C is the first rank without significant difference with -9°C and -18°C. Furthermore, acceptability in -18°C in 3 times is the first rank. The results of freezing time during 3 temperatures indicate that color, flavour and acceptability are not significantly different. The research results indicate that sensory attributes of the vegetables during 180 days frozen storage is affected by freezing temperature mainly rather than freezing time.  

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Change in chemical deterioration index (peroxide value, PV; thiobarbituric acid index, TBA; free fatty acids, FFA; total volatile basic nitrogen, TVB-N) and sensory properties (texture, general appearance and eye) of kutum (Rutilus frisii kutum) during 6 months frozen storage (-18 º C) was investigated. PV were increased until month 3, then decreased (P<0/05). During storage period the amount of TBA and FFA increased (P<0/05). TVB-N value did not follow a regular pattern but on the whole increased during storage period. None of the chemical quality parameters exceeded the acceptability limits. These results were supported by the results of sensory analyses. Results of this study showed that kutum has acceptable quality during 6 month frozen storage. 

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Changes in the fatty acid content, during frozen storage at -24°C of Caspian kutum (Rutilus frisii kutum), golden grey mullet (Liza aurata), common carp (Caprinus carpio), pike perch (Sander lucioperca) and common kilka (Clupeonella cultiventris caspia), caught from south Caspian Sea were studied in the present work. Changes in saturated fatty acids (SFAs), monounsaturated fatty acids (MUFAs), polyunsaturated fatty acids (PUFAs), ecosapentaenoic acid plus docosahexaenoic acid/palmitic acid (EPA+DHA/C16), n3 PUFA/n6 PUFA (n3/n6) and polyunsaturated fatty acids/saturated fatty acids (PUFA/SFA) were investigated during a six month period. Results indicated that due to the decrease in unsaturated fatty acids particularly PUFAs (9.25-23.03%), and lower ratios of n3/n6 (2.02-6.06), EPA+DHA/C16 (polyene index; 0.21-0.65) and PUFA/SFA (0.18-0.64) the poststorage nutritional values of these species significantly decrease.

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Changes in the fatty acid composition and biochemical indices of mackerel (which has a substantial lipid content) and shark (which has negligible lipid content) fillets stored at - 18°C for up to six months were measured. Lipid content was measured (6.35% and 1.38%) in mackerel and shark, respectively; however it decreased during frozen storage in both fish species. In analysis of fatty acids the amount of PUFA, especially
-3 ones, was more predominant in mackerel than shark, nevertheless, fatty acid composition has changed in both species during frozen storage. The amount of saturated fatty acids in contrast with unsaturated fatty acids increased due to oxidation of PUFA. The decrease in PUFA compounds (40.1% and 23.94%) was as follows:
-3 (48% and 42.83%),
-3/
-6 ratio (41.36% and 50%), PUFA/SFA ratio (56% and 42.23%) and EPA+DHA/C16 ratio (55.55% and 46.66%) in mackerel and shark, respectively. For both species, tiobarbituric acid (TBA), peroxide (PV), free fatty acids (FFA) and total volatile base nitrogen (TVB-N) values were significantly (P< 0.05) increased with storage time. The results showed that, among these indices, changes in the PV and TBA in mackerel were significantly (P< 0.05) larger than in shark; but changes of FFA and TVB-N in shark were significantly (P< 0.05) higher than in mackerel. It means that oxidative and hydrolytic deterioration are promoter factors of biochemical changes in mackerel and shark, respectively.