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    Effect of Freeze, Oven and Microwave Pretreated Oven Drying on Color, Browning Index, Phenolic Compounds and Antioxidant Activity of Hawthorn (Crataegus orientalis) Fruit
    (UNIV AGR SCI & VETERINARY MED CLUJ-NAPOCA, 2018) Coklar, Hacer; Akbulut, Mehmet; Kilinc, Semih; Yildirim, Ali; Alhassan, Iliasu
    Flowers, leaves and fruits of hawthorn plant are traditionally used for treating diseases like hypertension and atherosclerosis. The medicinal effects of the plant are generally attributed to its phenolic compounds. However, the fruits are perishable materials because of their high content of water, and generally dried and stored to be used outside its season. The main aim of this research was to investigate the effect of different drying methods on phenolic compounds of the hawthorn fruit. Fruits were collected from the wild growing trees in Turkey. De-seeded fruits were dried in freeze-, oven- (60 degrees C) and microwave pretreated oven drying (microwave application for 5 min at 360 W before drying at 60 degrees C) methods and analyzed for antioxidant activity, phenolic compounds, total phenolic content and color parameters. Total phenolic content of fresh hawthorn fruits was found as 13.36 mg g(-1) DW. Oven- and microwave pretreated oven drying methods had a reductive effect on total phenolic content and antioxidant activity of fruits when compared to freeze drying method. (-)-Epicatechin (994.10 mg kg(-1) DW), rutin (765.30 mg kg(-1) DW), and procyanidin B2 (553.80 mg kg(-1) DW) were the main phenolics of the fruit. Lowest values of these three compounds were observed in oven- dried fruits. Microwave pretreatment oven drying method resulted in browner product. Although the highest phenolic concentration and antioxidant activity were occurred in freeze-dried sample, microwave pretreatment before oven drying could be applied to reduce the time and cost of drying in terms of phenolic compounds and antioxidant activity.
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    Encapsulation of mahonia (Mahonia aquifolium) fruit anthocyanins with apricot tree gum and determination of its heat stability
    (Selçuk Üniversitesi Fen Bilimleri Enstitüsü, 2019) Alhassan, Iliasu; Çoklar, Hacer
    This study was conducted to investigate the encapsulation efficiencies of different wall materials (Apricot tree gum (ATG), Gum Arabic (GA), Apricot tree gum and Gum Arabic (ATG+GA) combination (50:50), Gum Arabic and Maltodextrin (MD+GA) combination (50:50), and Apricot tree gum and Maltodextrin (ATG+MD) combination (50:50)) were used to encapsulate Mahonia aquifolium anthocyanins by freeze drying. Then the thermal stabilities of the encapsulated samples were analyzed at three different storage temperature (35, 45 and 50 °C). The order of reaction best fitted in first order equation of kinetics. The highest encapsulation efficiency was determined in ATG+GA combination (98.96 %) and the least was found in ATG+MD (96.18 %). The encapsulation efficiencies of all the five wall materials were above 95 %. Generally, color degradation was significant in wall materials with MD (ATG+MD and GA+MD). Stability of L*, a*, and b* CIElab parameters were best in ATG. The lowest total color difference (ΔΕ) for all wall materials under all conditions were 2.77±0.23 and 4.98±0.24 at 45 and 50 °C for ATG and 0.31±0.97 at 35 °C for GA. The rate constant of reaction for ATG was 0.04, 0.06 and 0.08 day-1 at 35, 45 and 50 °C respectively while the activation energy (Ea) was 37.4221 ( kJ mol-1); R2 = 0.9892 appeared to protect the anthocyanins with less degradation throughout storing time.
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    ORGANIC ACIDS, SUGARS, PHENOLIC COMPOUNDS AND ANTIOXIDANT ACTIVITY OF Malus floribunda coccinella FRUIT, PEEL AND FLESH
    (WYDAWNICTWO AKAD ROLNICZEJ W LUBLINIE, 2018) Coklar, Hacer; Akbulut, Mehmet; Alhassan, Iliasu; Kirpitci, Seyma; Korkmaz, Emine
    Mains floribunda coccinella is a landscape tree that is generally planted for its pinky flowers and small reddish fruits. The red-fleshed fruits, called crab apples, are rich in anthocyanins and are assumed as an environmental pollution material during the fruit bearing season. The aims of this research were to determine the organic acids, sugars, sugar:acid ratio, color, phenolic compounds and antioxidant activity of the fruit and also to identify the phenolic compounds, monomeric anthocyanins content and antioxidant activities in the peel, flesh and whole fruit. Malic acid (25.394 g kg(-1) FW) was the main organic acid of the fruit. In fruits, amounts of sucrose, glucose and fructose were found to be 0.497, 0.504 and 4.334 g 100 g(-1) FW, respectively. Highest total phenolic concentration and antioxidant activity values were observed in the peel among the fractions, while protocatechuic and cinnamic acids, rutin, isorharrmetin-3-glucoside, quercetin, procyanidin B1, (+)-catechin and cyanidin-3-galactoside were predominant phenolics of the peel. Highest amounts of chlorogenic acid and (-)-epicatechin were determined in the flesh. Cyanidin-3-galactoside concentration in the flesh was approximately half the amount of that in the peel.