Tuncay Gumus

Effect of Gamma Irradiation on Total Phenolic Contents and Antioxidant Activities of Satureja Hortensis, Thymus Vulgaris, and Thymbra Spicata from Turkey

In this study, the effect of gamma irradiation on the total phenolic content and antioxidant activity of Satureja hortensis, Thymus vulgaris, and Thymbra spicata was evaluated. Plants irradiated in a 60Co irradiator to 0, 1.2, 3.0, and 5.1 kGy at 25°C. Control and irradiated samples were extracted with methanol. The antioxidant activity of methanol extracts was determined using phosphomolybdenum assay and the 1,1-diphenyl-2-picrylhydrazyl (DPPH) radical scavenging method. The total phenolic content in three spices was found to decrease with irradiation except at 5.1 kGy for S. hortensis. The DPPH radical scavenging activity of the extracts decreased after irradiation.

Effect of gamma-irradiation on some chemical characteristics and volatile content of linseed.

The effect of irradiation (2.5, 4.0, 5.5, and 7.0 kGy) on chemical properties and volatile contents of linseed was investigated. Consistent decreases were observed in both protein and oil content of the irradiated linseed samples with increasing irradiation doses. The ash content of the irradiated linseed samples increased significantly (P<.05) with increasing irradiation doses except for 5.5 kGy. Irradiation treatment caused irregular changes in palmitic and stearic acid content. Although styrene and p-xylene content decreased as a result of irradiation, 1-hexanol content only decreased at 7.0 kGy. Benzaldehyde, p-cymene, and nonanol were not determined at irradiation doses above 4.0 kGy.

Characteristics of grape seed and oil from nine Turkish cultivars

Percentages of crude oil, protein, fibre and ash of grape seeds obtained from Turkish cultivars were of the ranges 5.40–10.79, 5.24–7.54, 17.6–27.1, and 1.2–2.6, respectively. The highest crude oil, crude protein and crude fibre were determined in Siyah pekmezlik, Karadimrit and Antep grape seeds. The energy values of seeds were established to be between 102.28 and 148.07 kcal g−1. Potassium and calcium contents of seed samples were found to be at high levels compared to sodium. The seeds contained 686–967 ppm of Na, 2468–3618 ppm of K and 2373–4127 ppm of Ca. The refractive index, relative density, acidity, saponification value, unsaponifiable matter and iodine value of seed oils were determined to be in the ranges 1.474–1.477 , 0.909–0.934 25/25°C, 0.74–1.24%, 181–197, 0.91–1.66%, and 126–135, respectively. The main fatty acids were of the ranges 60.7–68.5% linoleic, 16.1–23.4% oleic and 8.0–10.2% palmitic. The highest percentages of linoleic acid (68.5%) was determined in Siyah pekmezlik seed oil.

Optimizing a submerged Monascus cultivation for production of red pigment with bug damaged wheat using artificial neural networks

The combined effect of temperature, agitation speed, and light on red pigment production by Monascus purpureus (M. purpureus) Went DSM 1604 using bug damaged wheat was studied using an artificial neural network (ANN). Information retrieved from the ANN was used to determine the optimal operating conditions for pigment production by M. purpureus using bug damaged wheat meal. The developed ANN had R2 values for training, validation, and testing data sets of 0.993, 0.961, and 0.944, respectively. According to the model, the highest pigment production of 1.874 absorbance units at 510 nm (A510 nm) would be achieved at 29°C and 150 rpm under light conditions. The mean value of the experimental results obtained under these optimum conditions was 1.787±0.072 A510 nm, corresponding to a pigment yield of 35.740 A510 nm/g. The study showed that bug damaged wheat can be used as a substrate for red pigment production by M. purpureus.

Nutritional and technological characteristics of olive (Olea europea L.) fruit and oil: two varieties growing in two different locations of Turkey.

Olea europea L. fruits were evaluated for weight, moisture, ash, crude protein, crude oil, energy, crude fibre, roundness, resistance against extra force and product density. The relative density, refractive index, free fatty acids, peroxide value, iodine value and unsaponifiables were determined in the olive oils. The main fatty acids identified by gas chromatography were palmitic acid (16:0), palmitoleic acid (16:1), stearic acid (18:0), oleic acid (18:1) and linoleic acid (18:2). Of the identified fatty acids, lauric acid (12:0), linolenic acid (18:3), arachidic acid (20:0), eicosenoic acid (20:1), behenic acid (22:0) and lignoseric acid (24:0) were found in trace amounts. As expected, the oleic acid content was the major fatty acid of olive oil. Oleic acid was represented in much higher concentrations than the other acids. The product roundness, resistance against extra force, product density and weight of 100 fruit were established as technological characteristics in olive fruit. The damage energy and the unit of volume deformation energy of the Memecik and Tavşanyüreği varieties were 1.36×10−3 J and 3.59×10−4 J/mm3 and 1.89×10−3 J and 5.10×10−4 J/mm3, respectively. The fruits showed a similar composition, and both fruit and oil contained unsaturated fatty acids.

The Effect of Oregano and Cinnamon Essential Oils on Fermentation Quality and Aerobic Stability of Field Pea Silages.

This study was performed to determine the effect of field pea silages which were the organic acid (OA) alternative of oregano and cinnamon essential oils on fermentation quality and aerobic stability. Whole crop pea was harvested at full pod stage and wilted in the laboratory at the 48 h. The chopped pea was mixed and divided into equal portions allocated to five groups: CON (non-treated), distilled water, denoted as control group; OA group, a mixture of 60% formic acid, 20% sodium formate and 20% water applied at a rate of 5 g/kg fresh forage (Silofarm Liquid, Farmavet); origanum (ORE) group, Origanum onites essential oil at 400 mg/kg fresh forage; cinnamon (CIN) group, cinnamon essential oil at 400 mg/kg fresh forage; origanum+cinnamon (ORECIN) group, a mixture of ORE and CIN applied at an equal rate of 400 mg/kg fresh forage. Cinnamon decreased acetic acid (AA), ammonia nitrogen (NH3-N) and weight loss (WL) at the end of 60 days silage. Crude protein (CP) and dry matter (DM) increased by cinnamon essential oil. Yeasts were not detected in any treatments, including the control, after 7 days of air exposure. The CO2 amount decreased and the formation mold was inhibited in the aerobic period by the addition of cinnamon oil. Oregano did not show a similar effect, but when it was used with cinnamon, it showed synergic effect on AA and during aerobic period, it showed antagonistic effect on mold formation and DM losses. It was found in this study that cinnamon can be an alternative to organic acids.