Cesarettin Alasalvar

Differentiation of cultured and wild sea bass (Dicentrarchus labrax): total lipid content, fatty acid and trace mineral composition

The proximate, fatty acid and trace mineral compositions in the flesh of cultured and wild sea bass (Dicentrarchus labrax) were evaluated. Cultured sea bass contained significantly (P 0.05) differences were noted in the total content of minerals examined. Thus, cultured and wild sea bass may be differentiated using total lipid content, fatty acid proportions and trace mineral compositions and these differences may be attributed to the constituents of the diet of the fish.

Freshness assessment of cultured sea bream (Sparus aurata) by chemical, physical and sensory methods

The quality changes of cultured sea bream (Sparus aurata) stored in ice for a period of up to 23 days were determined by K and related values, sensory assessment and texture by texturometer. Sensory schemes, based on the Tasmanian Food Research Unit (TFRU) scheme for raw fish and on the Torry scheme for cooked fish were modified to be appropriate for whole cultured sea bream, according to the trained panellists’ perceptions, during the storage period in ice. The TFRU sensory score of fish showed good agreement with K value and texture results throughout the storage period. The limit for acceptability of cultured sea bream stored in ice was about 17‐18 days. Generally, K, Ki and G values had good correlation with the degree of freshness and can be used as freshness indicators. # 2000 Elsevier Science Ltd. All rights reserved.

Antioxidant Activity of Hazelnut Skin Phenolics

Phenolic compounds were extracted from hazelnut skin using 80% (v/v) aqueous acetone or methanol. The crude extracts were applied onto a Sephadex LH-20 column for two fractionations (Fr. I and Fr. II). Fr. I consisting of low-molecular-weight phenolics was eluted by ethanol, whereas Fr. II consisting of tannins was obtained using acetone/water (1:1, v/v) as the mobile phase. UV spectra of phenolic compounds present in the crude extracts and their fractions exhibited a maximum absorbance at 282 nm. The crude extracts and their fractions were examined for phenolic and condensed tannin contents as well as total antioxidant activity (TAA), antiradical activity against the 2,2-diphenyl-1-picrylhydrazyl (DPPH) radical, and reducing power. Results of these assays showed higher values when Fr. II containing tannins was tested, followed by crude extract, and Fr. I. Both 80% acetone and methanol were capable of extracting phenolics, but 80% acetone was a more effective solvent for the extraction of condensed tannins (p < 0.05). These results suggest that hazelnut skin can be considered as a value-added byproduct for use as dietary antioxidants.

Tree Nuts: Composition, Phytochemicals, and Health Effects

Tree Nuts: Composition, Phytochemicals, and Health Effects: An Overview, C. Alasalvar and F. Shahidi Chemical Composition of Edible Nut Seeds and Its Implications in Human Health, S.K. Sathe, E.K. Monaghan, H.H. Kshirsagar, and M. Venkatachalam Health Benefits of Tree Nuts, M.E. Ternus, K. Lapsley, and C.J. Geiger Tree Nut Allergens, S.K. Sathe, G.M. Sharma, and K.H. Roux Sphingolipids in Tree Nuts, Y. Wang, D. Tan, and C.-T. Ho Health Aspects and Antiaflatoxigenic Activity of Phytochemicals in Tree Nuts, R.J. Molyneux, N. Mahoney, J.H. Kim, and B.C. Campbell Flavor and Volatile Compounds in Tree Nuts, K.R. Cadwallader and S. Puangpraphant Almond and Almond Products: Nutraceutical Components and Health Effects, F. Shahidi, Y. Zhong, S.S.K. Wijeratne, and C.-T. Ho Bioactives and Health Benefi ts of Brazil Nut, F. Shahidi and Z. Tan Bioactive Compounds from Cashew Nut and Its Coproducts, F. Shahidi and Z. Tan Chemical Composition and Health Aspects of Chestnut (Castanea spp.), F. Korel and M.O. Balaban Compositional Characteristics and Health Effects of Hazelnut (Corylus avellana L.): An Overview, C. Alasalvar, F. Shahidi, J.S. Amaral, and B.P.P. Oliveira Antioxidant Activities and Phytochemicals in Hazelnut (Corylus avellana L.) and Hazelnut By-Products, C. Alasalvar, A.M. Hoffman, and F. Shahidi Phytochemical Profi les and Potential Health Benefi ts of Heartnut (Juglans ailanthifolia var. cordiformis): A Comparison with the Common Walnut (Juglans regia L.), R. Tsao and L. Li Nutrient Composition and Health Beneficial Effects of Macadamia Nuts, I.A. Munro and M.L. Garg Compositional Characteristics and Health Effects of Pecan [Carya illinoinensis (Wangenh.) K. Koch], R.R. Eitenmiller and R.B. Pegg Nutraceutical Potential of Pine Nut, L. Yu and M. Slavin Phytochemicals and Health Aspects of Pistachio (Pistacia vera L.), N.P. Seeram, Y. Zhang, S. Bowerman, and D. Heber Walnut Polyphenols: Structures and Functions, T. Fukuda Index

Effects of roasting on the antioxidant status and phenolic profiles of commercial Turkish hazelnut varieties (Corylus avellana L.).

The effect of roasting on the antioxidant status and phenolic profiles of seven commercial Turkish hazelnut varieties (namely, Çakıldak, Foşa, Karafındık, Mincane, Palaz, Sivri, and Tombul) was assessed. Samples were examined for their total phenolics, oxygen radical absorbance capacity (ORAC) values, condensed tannins, and phenolic acids (free and bound forms). Significant losses (p < 0.05) in total phenolics (~66.3%), ORAC values (~41.6%), condensed tannins (~75.2), and phenolic acids (~42.7) were noted when the hazelnuts were roasted. Some variations both between and within natural and roasted hazelnuts were observed (p < 0.05). Phenolic acids were mainly found in the bound form. Gallic, protocatechuic, p-coumaric, and ferulic + sinapic acids were present in all hazelnut varieties, albeit to different extents, and the first two were dominant. Mincane, in roasted form, had the highest total phenolics, ORAC values, condensed tannins, and phenolic acids. This was due to the presence of some skin in roasted Mincane. No skin was left in all other varieties upon roasting. The present work suggests that roasting results in a significant loss in the antioxidant status and phenolic profiles because of the removal of the skin, which is a rich source of phenolics. It is highly recommended to consume natural hazelnut instead of the roasted counterpart to take advantage of all of the functional benefits of this nut.

Validated Method for the Characterization and Quantification of Extractable and Nonextractable Ellagitannins after Acid Hydrolysis in Pomegranate Fruits, Juices, and Extracts

Pomegranates are one of the main highly valuable sources of ellagitannins. Despite the potential health benefits of these compounds, reliable data on their content in pomegranates and derived extracts and food products is lacking, as it is usually underestimated due to their complexity, diversity, and lack of commercially available standards. This study describes a new method for the analysis of the extractable and nonextractable ellagitannins based on the quantification of the acid hydrolysis products that include ellagic acid, gallic acid, sanguisorbic acid dilactone, valoneic acid dilactone, and gallagic acid dilactone in pomegranate samples. The study also shows the occurrence of ellagitannin C-glycosides in pomegranates. The method was optimized using a pomegranate peel extract. To quantify nonextractable ellagitannins, freeze-dried pomegranate fruit samples were directly hydrolyzed with 4 M HCl in water at 90 °C for 24 h followed by extraction of the pellet with dimethyl sulfoxide/methanol (50:50, v/v). The method was validated and reproducibility was assessed by means of an interlaboratory trial, showing high reproducibility across six laboratories with relative standard deviations below 15%. Their applicability was demonstrated in several pomegranate extracts, different parts of pomegranate fruit (husk, peels, and mesocarp), and commercial juices. A large variability has been found in the ellagitannin content (150-750 mg of hydrolysis products/g) and type (gallagic acid/ellagic acid ratios between 4 and 0.15) of the 11 pomegranate extracts studied.

Effects of roasting on oil and fatty acid composition of Turkish hazelnut varieties (Corylus avellana L.)

Abstract A total of 18 natural and roasted hazelnut varieties (namely, Acı, Cavcava, Çakıldak, Foşa, Ham, İncekara, Kalınkara, Kan, Karafındık, Kargalak, Kuş, Mincane, Palaz, Sivri, Tombul, Uzunmusa, Yassı Badem, and Yuvarlak Badem), grown in the Giresun province of Turkey, were compared for their differences in oil content and fatty acid profiles. The oil content in natural and roasted hazelnut varieties ranged from 57.85% for Kargalak to 68.31% for İncekara and from 61.37% for Kargalak to 71.72% for İncekara, respectively. A total of 20 fatty acids were identified in oils extracted from different varieties of natural and roasted hazelnuts. Among the identified fatty acids in natural hazelnut oils, 18:1ω9 was the dominant fatty acid (ranging from 77.77 to 86.91%). Roasting had minor influence on the fatty acid profiles. These results suggest that semi-commercial hazelnut varieties are as good source of oils and possess valuable fatty acid profiles as commercial varieties (Tombul, Çakıldak, Foşa, Karafındık, Mincane, Palaz, and Sivri).

Smell perception during early pregnancy : no evidence of an adaptive mechanism

Objective  It has been suggested that nausea and vomiting in pregnancy is an evolutionary adaptive mechanism to avoid the ingestion of potentially harmful foods. It has also been suggested that the mechanism that triggers nausea and vomiting in pregnancy may be olfaction and that olfactory senses are invoked to provide this protection. This study aimed to test this theory in a systematic design.

Compositional, nutritional, and functional characteristics of instant teas produced from low- and high-quality black teas.

Two types of instant teas produced from low- and high-quality black teas were examined for their proximate composition, dietary fiber, minerals, water-soluble vitamins, total phenolic content, various antioxidant assays, phenolics (flavanols, condensed phenolics, and phenolic acids), alkaloids, and carotenoids as well as taste-active compounds (sugars, organic acids, and free amino acids). Some variations, albeit to different extents, were observed (p < 0.05) among these parameters between instant teas produced from low- and high-quality black teas. With respect to proximate composition, carbohydrate was the predominant component (56.68-59.84 g/100 g), followed by protein (19.31-19.86 g/100 g). Ash, moisture, and, to a lesser extent, dietary fiber and fat were also present in both instant teas. Thirteen minerals, four water-soluble vitamins, six flavanols, two alkaloids, three condensed phenolics, one phenolic acid, and one carotenoid were identified. Total phenolic content varied between 17.35 and 17.82 g of gallic acid equivalents (GAE)/100 g instant tea. With regard to antioxidant activities, three different assays such as oxygen radical absorbance capacity (ORAC), trolox equivalent antioxidant capacity (TEAC), and cupric ion reducing antioxidant capacity (CUPRAC) were measured. No significant differences (p > 0.05) in total phenolic, ORAC, TEAC, and CUPRAC contents between low- and high-quality instant teas were observed. With regard to taste-active compounds, 3 sugars, 5 organic acids, and 18 free amino acids were positively identified, of which fructose, tannic acid, and theanine predominated, respectively. The present work suggests that despite some differences, instant teas produced from low- and high-quality black teas should not be distinguished on the basis of their compositional, nutritional, and functional characteristics as well as taste-active compounds.

Effects of roasting on taste-active compounds of Turkish hazelnut varieties ( Corylus avellana L.).

The effect of roasting on taste-active components of 18 native hazelnut varieties, grown in the Giresun province of Turkey, was assessed. Samples were examined for their sugars, organic acids, condensed tannins, and free phenolic acids. Six sugars (fructose, glucose, sucrose, myo-inositol, raffinose, and stachyose), seven organic acids (oxalic, maleic, citric, malic, lactic, succinic, and acetic), and one phenolic acid (gallic acid) were positively identified in natural and roasted hazelnut varieties; among these, sucrose, malic acid, and gallic acid predominated, respectively. Total sugars among hazelnut varieties ranged from 1.99 to 4.94 g/100 g, organic acids from 0.96 to 2.72 g/100 g, condensed tannins from 3.99 to 40.56 mg of catechin equivalents/g, and gallic acid from 0.159 to 0.871 mg/100 g. Differences existed in the sugar and organic acid contents between natural and roasted hazelnut varieties, but they did not follow any particular trend. Significant losses (p < 0.05) in condensed tannins ( approximately 97.3%) and gallic acid ( approximately 66.7%) were noted when the hazelnuts were roasted. The present work suggests that roasting resulted in significant loss in condensed tannins and gallic acid due to the removal of the brown skin. The effect of roasting on sugars and organic acids was not noteworthy.