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    Application of multi pass high pressure homogenization to improve stability, physical and bioactive properties of rosehip (Rosa canina L.) nectar
    (Elsevier Sci Ltd, 2019) Sarıcaoğlu, Furkan Türker; Atalar, Ilyas; Yilmaz, Volkan A.; Odabas, Halil I.; Gul, Osman
    The effect of high pressure homogenization (HPH) on physical and bioactive properties of rosehip nectar was investigated. Rosehip nectar has a sedimentation problem while waiting on the market shelf during the sale, for solving this problem, nectars were passed 1, 2 and 3 times through 75, 100 and 125 MPa pressures. Mean particle size decreased as pressure and pass number increased (p < 0.05), whereas zeta potential did not change (p > 0.05). Microstructural images revealed that HPH treatment disrupted the cells and caused to release of cell materials to serum. HPH treatment increased the.E values (from 2.48 to 6.03). HPH treated samples showed no sedimentation during storage for 15 days. All samples showed shear thinning behavior and were characterized as weak gel network (G' > G ''). Total phenolic content and ascorbic acid results were decreased by HPH treatments due to increasing outlet temperatures of product, however, antioxidant capacity of nectars increased after treatment due to increasing total carotenoid content. This study indicated that HPH treatment could solve the sedimentation problem during shelf life with minimally affecting bioactive and physical properties of rosehip nectar.
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    Application of TOPSIS methodology to determine optimum hazelnut cake concentration and high pressure homogenization condition for hazelnut milk production based on physicochemical, structural and sensory properties
    (Springer, 2018) Gul, Osman; Atalar, Ilyas; Mortas, Mustafa; Sarıcaoğlu, Furkan Türker; Yazici, Fehmi
    Vegetable milks containing antioxidants, fatty acids and vitamins can be recommended as an alternative to animal milks cause some health problems like lactose intolerance and milk protein allergy. Hazelnut oil cake which is a waste from hazelnut oil production cannot be used for human nutrition. Cold press hazelnut cake must be evaluation as food materials. The aim of this study was to evaluate the effect of cold pressed hazelnut cake concentration (5, 10, 15% w/v) and high pressure homogenization (HPH) (up to 100MPa) on the physicochemical, structural and sensory properties of hazelnut milk and also determined the best conditions for hazelnut milk production by TOPSIS approach. Hazelnut milks produced from 15% hazelnut cake had the best physicochemical properties and physical stability, but the sensory properties of the milks were not acceptable due to viscoelastic behaviors. Physicochemical properties, physical stability and sensory characteristics of hazelnut milks were significantly affected by homogenization pressure (P<0.05). Colloidal stability and sensory properties of hazelnut milks were improved by increasing homogenization pressure. The viscosity values of hazelnut milks with 10 and 15% hazelnut cakes were significantly decreased by increasing the homogenization pressure. TOPSIS approach showed that 10% hazelnut cake concentration and 100MPa homogenization pressure was the best condition for an acceptable hazelnut milk production.
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    Effect of ultrasonication treatment on structural, physicochemical and bioactive properties of pasteurized rosehip (Rosa canina L.) nectar
    (Elsevier, 2020) Atalar, Ilyas; Sarıcaoğlu, Furkan Türker; Odabas, Halil I.; Yilmaz, Volkan A.; Gul, Osman
    The effect of ultrasonication process (US) on the physical and bioactive properties of pasteurized rosehip nectar was investigated. In order to solve sedimentation problem, two amplitude levels (50 and 100%) and different treatment times (5, 10, 15 and 30 min) were applied to rosehip nectars. Mean particle size decreased as amplitude and treatment time increased. US treatment caused to increase in redness and yellowness values of nectars and also color change was found noticeable as 1.9-2.6 at 100% amplitudes. US treated samples showed no sedimentation during storage for 15 days while control sample displayed 74% colloidal stability. All samples showed shear-thinning behavior and were characterized as weak gel network. Total phenolic and carotenoid contents and antioxidant activity was increased by US treatment, however, ascorbic acid content decreased. US treatment can be an alternative technology preventing sedimentation problems during shelf life with minimally affecting bioactive and physical properties of rosehip nectar.
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    High pressure homogenization of mechanically deboned chicken meat protein suspensions to improve mechanical and barrier properties of edible films
    (Elsevier Sci Ltd, 2018) Sarıcaoğlu, Furkan Türker; Tural, Serpil; Gul, Osman; Turhan, Sadettin
    The effect of high pressure homogenization (HPH) on edible films obtained from mechanically deboned chicken meat proteins (MDCM-P), a by-product of poultry industry, was investigated. Film forming suspensions (FFS) were prepared at 4% protein concentration and homogenized up to 150 MPa. FFSs were characterized in terms of particle size and steady shear rheology, whereas optical, barrier, mechanical and microstructural properties of resulting films were determined. Particle size of suspensions decreased as homogenization pressure increased, and suspensions treated up to 50 MPa showed shear thinning behavior with higher yield stress, while higher HPH treatment caused Newtonian flow. Shear stress-shear rate data were fitted to Herschel-Bulkley model. HPH treatment improved film appearance, and all films displayed good barrier properties against UV light which induces lipid oxidations in foods. The decreasing particle size of HPH treated MDCM-P suspensions up to 100 MPa caused lower water vapour permeability (WVP) and higher tensile strength (TS), and these results were also confirmed by film micrographs which had homogeneous, non-porous and un-cracked surface images. However, porous cross sectional images were observed from 150 MPa HPH treated films. FTIR spectra of films showed similar backbone structure, and the secondary structure of films was analyzed from the area of the deconvoluted Amide I peak, which changed significantly. ss-sheet and ss-turn contents of films showed high correlation coefficients with TS and EAB values. It can be concluded from this study that HPH applications up to 100 MPa can enhance the mechanical and barrier properties of films.
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    Influence of thermosonication (TS) process on the quality parameters of high pressure homogenized hazelnut milk from hazelnut oil by-products
    (Springer India, 2019) Atalar, Ilyas; Gul, Osman; Sarıcaoğlu, Furkan Türker; Besir, Aysegul; Gul, Latife Betul; Yazici, Fehmi
    Hazelnut, an important source of nutrition, is reasonably expensive for hazelnut milk production. Hazelnut cake, a by-product from hazelnut oil production by cold press extraction technique, does not contain any chemical residue and can be used for hazelnut beverage production. This study investigates the effects of thermosonication process on the quality parameters of hazelnut milks and also compares the observed results with the conventional thermal process. Different thermosonication conditions at different amplitude levels (40 and 60% amplitudes for 5, 10, 15, 20 and 25 min and 80% amplitude for 3, 5, 10 and 15 min) were studied for physicochemical and rheological properties, as well as microbial inactivation and bioactive compounds of hazelnut milk produced from the cold pressed hazelnut cake as byproduct of oil production. In general, sonication process significantly improved the total phenolic compounds, antioxidant activity, appearance and structural properties like syneresis, sedimentation, viscosity and consistency of samples. The application of thermosonication at 60% amplitude for 25 min and 80% amplitude for 15 min achieved complete inactivation of microorganisms (total aerobic mesophilic bacteria and yeast-mould). Complete inactivation of microorganisms was also achieved by conventional pasteurization at 85 degrees C, but this treatment caused some undesirable changes such as loses of bioactive compounds and deterioration of structural properties. The findings of the present study indicate that thermosonication can be successfully utilized for commercial processing of hazelnut milk with improved quality. This technique allows the production of hazelnut milks in safety and quality standards with highly nutritious then the conventional product.