Food Engineering / Gıda Mühendisliği

Permanent URI for this collectionhttps://hdl.handle.net/11147/12

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Subject: search.filters.subject.PhenolicsWoS Q: search.filters.wosQuartile.Q1

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Now showing 1 - 3 of 3
  • Article
    Citation - WoS: 118
    Citation - Scopus: 127
    Investigating the Effects of Food Matrix and Food Components on Bioaccessibility of Pomegranate (punica Granatum) Phenolics and Anthocyanins Using an In-Vitro Gastrointestinal Digestion Model
    (Elsevier Ltd., 2014) Şengül, Hafizenur; Sürek, Ece; Nilüfer Erdil, Dilara
    Effects of food matrix and individual food components on potential bioaccessibility of pomegranate were investigated by means of simulating in vitro gastrointestinal (GI) digestion. The foodstuffs (sunflower oil, skim milk, cooked lean meat, bread, skim yogurt, probiotic yogurt, apple, lemon, honey, soy milk, cream, and soybean) and the food components (gluten, casein, isolated meat protein, lactose, fructose, galactose, glucose, salt, ascorbic acid, starch, cooked starch, tocopherol, linoleic acid, cellulose, citric acid and pectin) were codigested with pomegranate in model systems to better understand matrix effects. Total phenolic content (TPC) and total anthocyanin content (TAC) were determined by spectrophotometric methods and major phenolics/anthocyanins were analyzed by RP-HPLC/PDA detection both before and after in vitro GI digestion at post gastric (PG), dialyzable (IN) and non-dialyzable (OUT) fractions. Phenolics of pomegranate were found to be stable during gastric conditions (115%), with 25% loss in pancreatic digestion, available (14%) in IN. Although preserved (89%) in PG, anthocyanins were lost in pancreatic digestion (38%), but still available (12%) in IN. Milk, bread, yogurt, probiotic yogurt, lactose, starch, cellulose, salt, citric acid or tocopherol codigestion with pomegranate decreased TPC for all fractions. Proteins affected losses in PG and OUT fractions. Carbohydrates such as starch, lactose, glucose and pectin appeared to affect the loss of phenolics and exerted 2-fold decreases in serum fraction (IN). For TAC, only meat, soymilk or cream codigestion with pomegranate resulted in IN losses. Proteins did not significantly affect TAC in IN, but were inhibitory in PG. However, carbohydrates and fatty acids significantly increased TAC in IN. Generally cyanidins were found to be more stable in food matrices and pancreatic conditions than other anthocyanins.
  • Article
    Citation - WoS: 14
    Citation - Scopus: 17
    Phenolics Profile of a Naturally Debittering Olive in Comparison To Regular Olive Varieties
    (John Wiley and Sons Inc., 2014) Aktaş, Ayşe Burcu; Özen, Banu; Tokatlı, Figen; Şen, İlknur
    BACKGROUND: Hurma, an olive variety that grows in a specific area in Turkey, loses its bitterness before harvesting, and therefore does not need further processing steps for the production of table olives. The total phenol content and phenolic profiles of (1) this naturally debittered olive type, Hurma; (2) the same olive variety, but not a naturally debittered type, Erkence; and (3) another variety, Gemlik, which is commonly consumed as table olive, were determined during their maturation period for two harvest years. RESULTS: The total phenol content of Hurma is the lowest compared to the other types regardless of harvest year, which has a significant effect on the phenolic content and composition of individual components for all olive types. All three olive types can be differentiated from each other especially during the late phase of maturation using the phenolics profile in combination with principal component analysis. CONCLUSION: The natural debittering phenomenon of Hurma olive on the tree involves a decrease in phenol content and a change in phenol composition. The differentiation in phenol composition especially becomes very significant in the late of period of maturation.
  • Article
    Citation - WoS: 94
    Citation - Scopus: 106
    Distribution of Simple Phenols, Phenolic Acids and Flavonoids in Turkish Monovarietal Extra Virgin Olive Oils for Two Harvest Years
    (Elsevier Ltd., 2009) Ocakoğlu, Derya; Tokatlı, Figen; Özen, Fatma Banu; Korel, Figen
    Monovarietal extra virgin olive oils extracted from six dominant and economically important Turkish olive cultivars (memecik, erkence, domat, nizip-yaglik, gemlik, ayvalik) were examined for their simple phenolics, phenolic acids and flavonoid compounds over 2005 and 2006 harvest years. Total phenol contents, oxidative stabilities and chromatic ordinates as colour parameters were also measured. The most typical phenolic compounds that were identified in both years are hydroxytyrosol, tyrosol, vanillic acid, p-coumaric acid, cinnamic acid, luteolin, and apigenin. Multivariate data were analysed by principal component and partial least square-discriminant analyses. It was observed that phenolic profiles of olive oils depended highly on harvest season. In addition, oils of different olive cultivars have different distribution of phenols. No significant correlation was observed between oxidative stability and phenolic compounds. Increase in peroxide value over an accelerated oxidation period of 11 days showed weak correlations with total phenol content, vanillin, syringic acid and colour parameter a*, as 0.56, 0.55, -0.42, and 0.51, respectively, in terms of correlation coefficient r.