Effect of different oil extraction methods on bioactive compounds, antioxidant capacity and phytochemical profiles of raw flaxseeds (Linum usitatissimum) and after roasting at different temperatures.

BACKGROUND: Factors such as variety, genetics, soil structure and plant diseases affect the oil amount and properties of flaxseed. By applying heat and various extraction treatments to flaxseed, the storage ability of the seed is increased by the removal of moisture, and the stability of phytochemicals in the seed against heat can be determined. RESULTS: Total carotenoid and phenol of flaxseeds changed from 0.13 (control) and 0.61 mg g-1 (120 °C) to 202.64 (control and 90 °C) and 225.69 mg 100 g-1 (120 °C), respectively. While total flavonoid of flaxseed roasted at different temperatures varied between 636.0 (90 °C) and 786.00 mg 100 g-1 (120 °C), antioxidant activity values for raw and roasted flaxseeds between 59.32% (control) and 68.64% (120 °C) were recorded. Oil content of seeds changed between 34.07 and 42.57% (P < 0.05). Viscosity of flaxseed oil extracted using different systems was between 31.95 (cold-pressed; control) and 36.00 mPa s (ultrasonic; 120 °C). The dominant phenolics of flaxseeds were identified as isorhamnetin, resveratrol, quercetin, catechin, apigenin-7-glucoside and campherol. The oils of flaxseeds contained 55.27-58.23 linolenic, 17.40-18.91 oleic, 14.03-14.84 linoleic and 4.97-5.37 palmitic acids, depending on extraction method and roasting temperature. CONCLUSION: Roasting and oil extraction methods did not have a significant effect on free acidity, but was found to affect peroxide value. The predominant phenolic constituents of flaxseed samples were isorhamnetin, resveratrol, quercetin, catechin, apigenin-7-glucoside and campherol, respectively. The major fatty acids of flaxseed oil were determined as linolenic, oleic, linoleic and palmitic. © 2023 Society of Chemical Industry.

Bioactive Compounds Extracted from Saudi Dates Using Green Methods and Utilization of These Extracts in Functional Yogurt.

The bioactive compounds of four Saudi date flesh extracts (Ambara (AF), Majdool (MF), Sagai (SF), and Sukkari (SKF)) prepared using different extraction methods-namely, supercritical fluid extraction (SFE), subcritical CO2 extraction (SCE), and Soxhlet extraction (SXE)-were evaluated. A total of 19 bioactive compounds were detected in extracts prepared using SFE and SCE methods, whereas less than 12 compounds were detected in extracts obtained using the SXE method. Both the date variety and extraction method affected the phenolic profile of date flesh extract (p ≤ 0.05). The apparent viscosity, surface color, and bioactive properties of yogurt were affected by both date flesh extracts and storage duration in varied magnitudes (p ≤ 0.05). The incorporation of date flesh extracts into yogurt formulations increased the total phenolic content (TPC), DPPH antiradical activity, viscosity, and redness (a*) and decreased the lightness (L*) and yellowness (b*) of the developed product (p ≤ 0.05). The elongation of storage time progressively (p ≤ 0.05) reduced the pH, TPC, DPPH antiradical activity, bacterial counts, and L* and b* values and increased the acidity, syneresis, viscosity, and a* values with few exceptions. Date flesh extracts can improve the health quality of yogurt without major influence on the sensory attributes while stored at 4 °C.

Effects of Functional Coatings Containing Chitosan, Orange Peel and Olive Cake Extracts on the Quality Attributes of Cucumber during Cold Storage.

This study investigated the effect of functional coating using 2% chitosan and different concentrations of olive cake extract (OCE) and orange peel extract (OPE) on the physicochemical quality attributes of cucumber during cold storage at 4 °C for 21 days. Both coating and storage influenced (p ≤ 0.05) the physicochemical attributes of cucumber. The highest values of moisture content, total soluble solids (TSS), pH, total phenolic contents (TPC), DPPH radical scavenging activity, yellowness (b*), and hardness were found in coated samples, which also showed the lowest values of the lightness (L*), greenness (a*), total viable count (TVC), yeast and mold counts, and acidity (p ≤ 0.05). Uncoated cucumber samples showed the highest (p ≤ 0.05) levels of acidity, lightness, greenness, TVC, and yeast and mold count. During storage, concomitant (p ≤ 0.05) reduction in moisture, TSS, pH, TPC, DPPH radical scavenging activity, L*, a*, b*, and hardness along with concurrent (p ≤ 0.05) increment in acidity, TVC, and yeast and mold count were evident in all cucumber samples. Interestingly, the changes in the aforementioned attributes were minimal in functionally coated samples in comparison to uncoated ones, suggesting the potential of OCE and OPE to preserve quality attributes of cucumber during cold storage.

Clove Polyphenolic Compounds Improve the Microbiological Status, Lipid Stability, and Sensory Attributes of Beef Burgers during Cold Storage.

This study investigated the phenolic composition of clove powder extract (CPE), determined by high-pressure liquid chromatography, as well as the effect of the clove powder (CP) concentration (0, 2, 4, and 6%) on the quality of beef burgers during 21 days of cold storage at 4 °C. The CPE contained a high amount of total phenolic content (455.8 mg Gallic acid equivalent/g) and total flavonoid content (100.4 mg catechin equivalent/g), and it exhibited high DPPH antioxidant scavenging activity (83.9%). Gallic acid, catechol, and protocatechuic acid were the highest phenolic acids (762.6, 635.8, and 544.9 mg/100 g, respectively), and quercetin and catechin were the highest flavonoid acids (1703.1 and 1065.1 mg/100 g, respectively). Additionally, the CPE inhibited the growth of both Gram-positive and Gram-negative bacteria effectively at 100 µg/disc. The addition of the CP had no discernible influence on the pH of the meat patties. The addition of CP at 4 and 6% increased the phenolic content and antioxidant activity of the beef patties, which consequently resulted in reduced lipid oxidation and microbial spoilage throughout the storage period. Furthermore, the CP significantly (p ≤ 0.05) improved the beef burger cooking characteristics (cooking yield, fat retention, moisture retention, and shrinkage). Additionally, the sensory acceptability was higher (p ≤ 0.05) for the burgers that contained 2% and 4% CP compared with the other treatments. In conclusion, the bioactive compounds in CP can extend the shelf life and improve the safety of beef burgers.

Quality Attributes of Refrigerated Barhi Dates Coated with Edible Chitosan Containing Natural Functional Ingredients.

Edible chitosan coatings with natural functional ingredients were used to preserve quality attributes of fresh Barhi date fruit. Fruits were coated with chitosan and/or 1 and 2% olive cake extract (OCE) or orange peel extract (OPE). Both coated and uncoated fruits were stored at 4 °C for 4 weeks. A slight decrease in the pH and increase in acidity with storage was observed. However, when chitosan was mixed with OCE or OPE, an increase in pH was observed with a concomitant decrease in acidity. The phenolic content of the samples was decreased with time. However, coating the date with OCE or OPE significantly (p ≤ 0.05) increased the total phenolic with a concomitant increase in radical scavenging activity. The textural properties, particularly hardness, were better preserved in case of coated dates. The sensory evaluation data showed non-significant changes in the acceptability of the Barhi dates throughout the storage period. Chitosan-coating significantly (p ≤ 0.05) inhibited mold growth over time. Scanning electron microscope (SEM) imaging showed difference among different coatings. According to principal component analysis (PCA), OCE and OPE were found to have protective effects on fruit quality.

Extraction and Evaluation of Bioactive Compounds from Date (Phoenix dactylifera) Seed Using Supercritical and Subcritical CO2 Techniques.

Date (Phoenix dactylifera) seed is a potential source of natural antioxidants, and the use of innovative green and low temperature antioxidant recovery techniques (using CO2 as solvent) such as supercritical fluid (SFE) and subcritical (SubCO2) extractions can improve their yields and quality in the extracts. SFE, SubCO2 and Soxhlet techniques were employed to enrich antioxidants in extracts from Sukari (SKSE), Ambara (AMSE), Majdool (MJSE) and Sagai (SGSE) date seeds. Extract yields were evaluated and modelled for SFE extract using response surface methodology. Significantly higher (p < 0.05) phenolics (143.48−274.98 mg GAE/100 g), flavonoids (78.35−141.78 mg QE/100 g), anthocyanins (0.39−1.00 mg/100 g), and carotenoid (1.42−1.91 mg BCE/100 g) contents were detected in extracts obtained using SFE and SubCO2 methods. The evaluation of in vitro antioxidant properties showed that SFE and SubCO2 seed extracts demonstrated promising antioxidant (13.42−23.83 µg AAE/mL), antiradical (228.76−109.69 µg/mL DPPH IC50), ferric reducing antioxidant power (1.43−2.10 mmol TE/100 g) and ABTS cation scavenging (375.74-717.45 µmol TE/100 g) properties that were significantly higher than Soxhlet extracts. Both SFE and SubCO2 techniques can be effectively utilized as innovative and environmentally friendly alternatives to obtain high quality antioxidant rich extracts from date seed. These extracts may have potential functional and nutraceutical applications.

Investigation of the Potential Use, Phytochemical and Element Contents of Acacia Plant Seeds Grown in Wild Form, Considered as Environmental Waste.

In this study, the effect of altitude on oil amounts, antioxidant activity, polyphenol content and mineral contents of Acacia seeds collected from two different locations (up to 1100 m above sea level) was investigated. Total carotenoid and flavonoid contents of Acacia seeds were detected as 0.76 (Konya) and 1.06 µg/g (Tasucu-Mersin) to 1343.60 (Konya) and 184.53 mg/100 g (Tasucu-Mersin), respectively. Total phenol contents and antioxidant activity values of Acacia seeds were identified as 255.11 (Konya) and 190.00 mgGAE/Tasucu-Mersin) to 64.18% (Konya) and 75.21% (Tasucu-Mersin), respectively. The oils extracted from Acacia seeds in Konya and Mersin province contained 62.70% and 70.39% linoleic, 23.41% and 16.03% oleic, 6.45%and 6.04% palmitic and 2.93% and 4.94% stearic acids, respectively. While 3,4-dihydroxybenzoic acid amounts of seeds are determined as 3.89 (Konya) and 4.83 mg/100 g (Tasucu-Mersin), (+)-catechin contents of Acacia seeds were identified as 3.42 (Konya) and 9.51 mg/100 g (Tasucu-Mersin). Also, rutintrihydrate and ferulic contents of Acacia seeds were found as 23.37 (Konya) and 11.87 mg/100 g (Tasucu-Mersin) to 14.74 mg/100 g (Konya) and 1.12 mg/100 g (Tasucu-Mersin), respectively. Acacia seeds collected from Konya and Mersin contained 4003.75 and 3540.89 mg/kg P, 9819.12 and 16175.69 mg/kg K, 4347.47 and 5078.81 mg/kg P, 2195.77 and 2317.90 mg/kg Mg, 1015.75 and 2665.60 mg/kg S and 187.53 and 905.52 mg/kg Na, respectively.

Changes in Fatty Acid, Tocopherol and Sterol Contents of Oils Extracted from Several Vegetable Seeds.

Oil contents of seeds changed between 15.89 g/100 g (purslane) and 38.97 g/100 g (black radish). Palmitic acid contents of oil samples were found between 2.2 g/100 g (turnip) and 15.0 g/100 g (purslane). While oleic acid contents of oil samples change between 12.1% (turnip) and 69.8% (purple carrot), linoleic acid contents of oils were determined between 8.9% (black radish) and 57.0% (onion). The highest linolenic acid was found in purslane oil (26.7%). While α-tocopherol contents of oil samples range from 2.01 mg/kg (purple carrot) to 903.01 mg/kg (onion), γ-tocopherol contents of vegetable seed oils changed between 1.14 mg/kg (curly lettuce) and 557.22 mg/kg (purslane). While campesterin contents of seed oils change between 203.2 mg/kg (purple carrot) and 2808.5 mg/kg (cabbage Yalova), stosterin contents of oil samples varied from 981.5 (curly lettuce) to 4843.3 mg/kg (purslane). The highest brassicasterin and δ5-avenasterin were found in red cabbage oil (894.5 mg/kg) and purslane seed oils (971.3 mg/kg), respectively. Total sterol contents of seed oils changed between 2960.4 mg/kg (purple carrot) and 9185.1 mg/kg (purslane). According to the results, vegetable seeds have different bioactive compound such as fatty acid, tocopherol and phytosterol.

The Effect of Plant Essential Oil and Extracts on Fatty Acid Profile of Virgin Olive Oil Stored in Different Packaging Materials.

In this study, the combined effect of different packaging materials (transparent PET, transparent glass, glass-PET bottle and tin), some aromatic herbs (thyme, rosemary, sage and olive leaf) and also their essential oils (thyme, rosemary and sage) on fatty acid composition of virgin olive oil was investigated during storage period. The initial amounts of the main fatty acids as oleic, palmitic and linoleic acids were determined as 72.89%, 11.89% and 8.96%, respectively. The addition of aromatic plants and essential oils did not effect the fatty acid profile. Also, packaging materials had a minor influence on fatty acids. In the 6th month of storage, the oleic acid contents of olive oils showed the increase in all of samples. The highest increase was observed in olive oil stored in glass-PET (74.30-75.01%), followed by stored in glass bottle (73.41-74.82%). Generally, during the storage, the differences of fatty acid contents were in minor level. The fatty acid composition of olive oils stored under different essential oil and extract concentrations showed partial differences depending on the extract type and concentration.

Phenolic Compounds, Antioxidant Activity and Fatty Acid Composition of Roasted Alyanak Apricot Kernel.

The oil recovery from Alyanak apricot kernel was 36.65% in control (unroasted) and increased to 43.77% in microwave-roasted kernels. The total phenolic contents in extracts from apricot kernel were between 0.06 (oven-roasted) and 0.20 mg GAE/100 g (microwave-roasted) while the antioxidant activity varied between 2.55 (oven-roasted) and 19.34% (microwave-roasted). Gallic acid, 3,4-dihydroxybenzoic acid, (+)-catechin and 1,2-dihydroxybenzene were detected as the key phenolic constituents in apricot kernels. Gallic acid contents varied between 0.53 (control) and 1.10 mg/100 g (microwave-roasted) and 3,4-dihydroxybenzoic acid contents were between 0.10 (control) and 0.35 mg/100 g (microwave-roasted). Among apricot oil fatty acids, palmitic acid contents ranged from 4.38 (oven-roasted) to 4.76% (microwave-roasted); oleic acid contents were between 65.73% (oven-roasted) and 66.15% (control) and linoleic acid contents varied between 26.55 (control) and 27.12% (oven-roasted).

Influence of Drying Methods on Bioactive Properties,Fatty Acids and Phenolic Compounds of Different Parts of Ripe and Unripe Avocado Fruits.

All drying processes increased oil content, antioxidant activity, total phenolic contents, and most of the phenolic compounds in the pulp, peel and seeds of both ripe fruits with varied degrees (p < 0.05). In addition, the processes reduced the oil contents, linoleic acids, 3,4-dihydroxybenzoic acid, (+)-catechin, and naringenin of the pulp, antioxidant activity of the peels and seeds, and 3,4-dihydroxybenzoic acid, (+)-catechin of the seeds and it enhanced all other parameters in the pulp, peel, and seeds of unripe fruits (p < 0.05). Comparing the phenolic profiles of avocado pulp, peels, and seeds of ripe and unripe fruits indicated that the peel and seeds are richer than the pulp and that is superior in unripe fruits than ripe ones. In addition, drying processes particularly microwave and air drying greatly enhanced the bioactive properties of ripe and unripe avocado fruits and could thus be used to elongate the shelf-life of avocado fruit products without major impact on the overall quality.

Bioactive compounds, nutritional and sensory properties of cookies prepared with wheat and tigernut flour.

This study aimed to evaluate cookies made with wheat (0%, 80%, 60%, and 50%) and tigernut flour (0%, 20%, 40%, and 50%) from two different sources. Standard methods were applied to determine the chemical properties, phenolic component, fatty acid composition, mineral content, and sensory properties of cookies. Tigernut flour from both sources was rich in oil, and total and individual phenolics, but with low antioxidant activity compared to wheat flour. The addition of tigernut flour to wheat resulted in increase of the content of bioactive compounds, minerals, and fatty acid contents of cookies. The cookies produced by formulating wheat with tigernut had a comparable organoleptic quality scores to wheat flour cookies. The production of cookies with both wheat and tigernut flour showed that this mixture is an interesting opportunity to have a functional product rich in bioactive compounds and considered satisfactory by consumers.

Influence of drying techniques on bioactive properties, phenolic compounds and fatty acid compositions of dried lemon and orange peel powders.

Lemon peel powder (LPP) obtained after drying (microwave, infrared, and oven) showed the lowest (58.72%) DPPH-radical scavenging activity in oven-dried and the highest (67.84%) in infrared-dried LPP while that of fresh lemon peel remained 63.22%. Orange peel powder (OPP) showed the lowest DSA (61.65) after microwave and the lowest (63.54%) after infrared-drying while that of fresh orange peel was 63.48%. Total phenolics were between 114.58 (fresh) and 179.69 mgGAE/100 g (oven) in LPP and between 158.54 (fresh) and 177.92 mgGAE/100 g (infrared) in OPP. The total flavonoid contents were 380.44 (fresh)-1043.04 mg/100 g (oven) in case of LPP and 296.38 (fresh)-850.54 mg/100 g (oven) in case of OPP. The gallic acid contents were 2.39 (fresh)-14.02 mg/100 g (oven) in LPP. The (+)-catechin contents were 1.10 (fresh)-49.57 mg/100 g (oven) for LPP and 0.82 (fresh)-7.63 mg/100 g (infrared) in case of OPP. The oleic acid content was 22.99 (infrared)-58.85% (fresh) in LPP-oil and 28.59 (microwave)-61.65% (fresh) in OPP-oil. The linoleic acid contents were 13.76 (fresh)-36.90% (oven) in LPP-oil and 14.14 (fresh)-37.08% (infrared) in case of OPP-oil. The drying techniques showed profound but variable effects on radical scavenging activity, total phenolics, flavonoid, carotenoids, phenolic compounds and fatty acid composition of both LPP and OPP and oven-drying (60 °C) was the most effective in improving these bioactive constituents.

Evaluation of nutritional status of foreign students at King Saud University, Kingdom of Saudi Arabia.

OBJECTIVE: The current study was conducted to assess the nutritional status and associated risk factors among foreign students residing at King Saud University for different periods and to explore its correlations. DESIGN: A cross-sectional study was conducted during the spring semester of 2018. A total of 400 male students aged 18-35 years had participated in the current study after signing a written consent form according to Helsinki Declaration. SETTING: A structural questionnaire was used to collect data on daily food intake and habits and socio-economic characteristics. Nutrients of food intake were assessed using the Esha programme and compared with that of dietary requirement intake (DRI). A body composition analyser was used to measure body fat (BF), visceral fat (VF) and BMI. Spearman correlation coefficients and simple regression analysis were performed to determine associations between variables. PARTICIPANTS: Foreign students residing for different periods (<6 months: 200 students and >6 months: 200 students) were used as subjects. RESULTS: The students who stayed <6 months consumed lower level of some nutrients than that of the DRI compared with those stayed >6 months. Overweight and obesity were more common among students who stayed >6 months with high values of BF and VF. Several risk factors were positively or negatively correlated with the students' nutrition proxies. CONCLUSION: Most of the students who stayed >6 months are suffered from overweight. Some independent variables were found to be significantly correlated with the students' nutrition proxies either positively or negatively.

Effect of conventional oven roasting treatment on the physicochemical quality attributes of sesame seeds obtained from different locations.

The impacts of conventional oven roasting at different temperatures and for different times on the physicochemical attributes of sesame seeds obtained from different regions was assessed. The color characteristics (a*, b*, and L* values), ash, moisture, protein, oil, total phenolic, and antioxidant activity of raw sesame seeds and the peroxide value, p-anisidine, fatty acids, and tocopherols of sesame oil varied with source. Oven roasting temperature and time significantly affected the physicochemical properties and bioactive components of sesame seeds and the oil quality from different countries. Roasting variably increased the a* value, antioxidant activity, protein, oil, total phenolic, and tocopherol content, and p-anisidine and peroxide values, whereas it reduced b* and L* values, moisture, and linolenic acid content of sesame seeds from different countries. Roasting conditions and growing locations affected the physiochemical composition and bioactive compounds of seeds. Such factors can influence the quality attributes of sesame seeds and oil and should be considered during processing.

Effect of almond genotypes on fatty acid composition, tocopherols and mineral contents and bioactive properties of sweet almond (Prunus amygdalus Batsch spp. dulce) kernel and oils.

Oil content of almond kernels ranged from 36.7% in the cultivar T12 to 79.0% in genotype T27. The major fatty acid in almond oil is oleic (62.43% in T7-76.34% in T4) followed by linoleic (13.97% in T4-29.55% in T3) and palmitic (4.97% in T2-7.51% inT3). The main tocopherol in almond oil was α-tocopherol (44.25 mg/100 g in T25-75.56 mg/100 g in T13) that was 44 folds higher than other tocopherols in the oil. Total tocopherol contents of almond oils ranged between 47.42 mg/100 g (T14) and 80.15 mg/100 g (T16). Among macro minerals, K was the highest (5238-14,683 mg/kg), followed by P (3475-11,123 mgkg), Ca (1798-5946 mg/kg), and Mg (2192-3591 mg/kg), whereas Na was the least (334-786 mg/kg) in almond kernel. The total polyphenol was observed in T16 (98.67 mg GAE/100 g), while the least was found in T24 (23.75 mg GAE/100 g). Antioxidant activity was high in T7 (91.18%) and low in T12 (44.59%).

Determination of Bioactive Lipid and Antioxidant Activity of Onobrychis, Pimpinella, Trifolium, and Phleum spp. Seed and Oils.

In this study, bioactive lipid components such as fatty acid composition, tocopherol and total phenolics content and antioxidant activity of few wild plant seed extracts were determined. The oil contents of seed samples changed between 3.75 g/100 g (Onobrychis viciifolia Scop) and 17.94 g/100 g (Pimpinella saxifrage L.). While oleic acid contents of seed oils change between 10.4% (Trifolium repens) and 29.5% (Onobrychis viciifolia Scop), linoleic acid contents of oil samples varied from 16.3% (Onobrychis viciifolia Scop) and 64.2% (Trifolium repens) (p < 0.05). While α-tocopherol contents of oil samples change between 2.112 (Pimpinella saxifrage L.) and 228.279 mg/100 g (Trifolium pratense), É£-tocopherol contents ranged from 0.466 (Phleum pratense) to 67.128 mg/100 g (Onobrychis viciifolia Scop). Also, α-tocotrienol contents of Onobrychis viciifolia Scop and Phleum pratense were 30.815 and 23.787 mg/100 g, respectively. Results showed some differences in total phenol contents and antioxidant activity values of extracts depending on plant species. The present study indicates that this seed oils are rich in fatty acid and tocopherol.

Influence of Thermal Processing on Oil Contents, Bioactive Properties of Melon Seed and Oils.

The oil content and the fatty acid composition of roasted and unroasted melon seed and oils were determined. The oil contents of roasted melon seeds changed between 26.4% (Type 12) and 38.7% (Type 4). In general, oil contents of roasted melon seeds were found higher than that of unroasted seeds that could be due to the evaporation of water during roasting processes which consequently lead to increased concentrations of other seed components including oils. Saturated fatty acid contents of unroasted melon seed samples change between 13.5% (Type 6) and 17.1% (Type 20). In addition, polyunsaturated fatty acids of unroasted melon seed oils ranged from 51.9% (Type 13) to 70.2% (Type 6). Palmitic acid contents of roasted seed oils varied between 7.8% (Type 5) and 15.1% (Type 17). In addition, the oleic acid contents ranged from 15.4% (Type 10) to 37.7% (Type17). Also, linoleic acid contents were found between 34.7% (Type 17) and 70.3% (Type 6). Saturated fatty acid contents of roasted melon seed oils ranged from 13.5% (Type 6) to 16.7% (Type 13). The major tocopherols in both roasted and unroasted melon seed oils were α-tocopherol, É£-tocopherol and δ-tocopherols. Melon seed oils are rich in linoleic, oleic acids and É£-tocopherol.

Effect of Frying on Physicochemical and Sensory Properties of Potato Chips Fried in Palm Oil Supplemented with Thyme and Rosemary Extracts.

Quality parameters of potato chips (flat and serrated) fried either in palm oil (PO) alone or containing natural (thyme (TPO) and rosemary (RPO) extracts) and synthetic BHT (BPO) antioxidants were evaluated during storage period. The free fatty acid and peroxide values of chips fried in PO (control) were found between 0.18 and 0.21% to 1.00 and 1.04 meqO2/kg during the first storage month, respectively. However, these values were 0.07-0.10% and 0.55-0.90 meqO2/kg for chips fried in TPO, respectively. The water contents increased when storage time increased from 1 to 7 month and their values changed between 0.49 and 1.95% (flat potato chips in BPO) and between 0.88 and 1.24% (serrated potato chips in TPO). The total trans-fat contents were 0.13% (serrated potato chips in BPO) and 0.35% (both flat and serrated potato chips in PO) at the start of storage. The total trans-fat content after 7 months were 0.13% (PO fried flat and serrated potato chips) and 0.17% (serrated potato chips fried in BPO, TPO and RPO). The acrylamide contents varied between 152 (serrated potato chips in PO) and 540 µg/kg (flat potato chips fried in RPO) at the beginning of storage. However, the acrylamide contents changed during 7th storage month and ranged from 182 (serrated potato chips in PO) to 518 µg/kg (flat potato chips in RPO). Among fatty acids, while palmitic acid are determined between 37.14 (flat chips in PO) and 41.60% (serrated chips in TPO), oleic acid varied between 30.0 (flat chips in RPO) and 33.00% (serrated chips in PO). Sensory evaluation showed that PO containing antioxidants showed better consumer preference for potato chips until the end of storage.

Effect of Microwave Treatment on Oil Contents, Fatty Acid Compositions and Mineral Contents of Hazelnut Varieties.

The oil content of both 'raw' and hazelnut kernels was significantly (p < 0.05) reduced as the microwave power increased from 180 W to 360 W. The contents of fatty acids flucuated for all varieties with microwave power, with a significant (p < 0.05) increment observed for 'Sivri' hazelnut at 180 and 720 W. The maximum linoleic acid contents for 'Raw', 'Sivri' and 'Tombul' hazelnuts were found as 11.87%, 12.61% and 17.68% for nuts roasted at 540 W, unroasted and those roasted at 720 W, respectively. It was observed that K (9735.1 mg/kg) and Mg (2343.7 mg/kg) contents of the investigated samples were found at the maximum levels in unroasted 'Tombul' hazelnut, while the highest P (2845.0 mg/kg) and S (1795.3 mg/kg) contents are determined for hazelnut roasted at 720 W (p < 0.05). The highest Ca content in hazelnut kernel was also observed at 360 W with 2400.9 mg/kg. However, roasting process did not dramatically affect the mineral contents of samples.