Browsing by Author "Alwazeer, Duried"

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Effect of Fortification of Set-Type Yoghurt With Different Plant Extracts on Its Physicochemical, Rheological, Textural and Sensory Properties During Storage
(Wiley, 2021) Bulut, Menekse; Tuncturk, Yusuf; Alwazeer, Duried
The effects of yoghurt fortification with rhubarb (RE), grape seed (GSE), thyme (TE), green tea (GTE) and mint (ME) extracts on the physicochemical, rheological, textural and sensory properties during cold storage were investigated. The syneresis value of the extract-fortified yoghurts was higher and the colour was lighter in comparison with control sample. The values of texture parameters such as firmness and consistency in RE and TE samples were higher than of CS, and all extract-fortified samples, except GSE, showed higher cohesiveness and viscosity. The ME-fortified yoghurt was found tastiest with the highest overall appreciable score. These food-agriculture wastes could be valorised for improving the nutritional and textural properties of yoghurt.
The Effects of Hydrogen Incorporation in Modified Atmosphere Packaging on the Formation of Biogenic Amines in Cold Stored Rainbow Trout and Horse Mackerel
(Academic Press inc Elsevier Science, 2022) Sezer, Yasemin Celebi; Bulut, Menekse; Boran, Gokhan; Alwazeer, Duried
The formation of biogenic amines (BAs) in fish products during storage forms a serious challenge to producers and is generally related to the growth of decarboxylase-producing microorganisms. Controlling the formation of BAs is a serious challenge for the fishery industry. This study evaluates the impact of incorporating molecular hydrogen (H-2) in a modified atmosphere packaging on the formation of BAs in both freshwater and seawater fish, i.e., rainbow trout and horse mackerel, respectively, stored at + 4 degrees C for 15 days. Fish samples were packaged in modified atmosphere packaging [MAP1 (50% CO2/50% N-2) and MAP2 (60% CO2/40% N-2)], reducing atmosphere packaging [RAP1 (50% CO2/46% N-2/4% H-2) and RAP2 (60% CO2/36% N-2/4% H-2)], and under air (control). The amount of BAs, except spermidine and spermine, significantly increased during storage in all treated samples. Both MAPs and RAPs showed significant restrictive effects on the formation of heterocyclic, aromatic, and aliphatic di-amines (histamine, tyramine, putrescine, cadaverine) in both fish species, with a more potent effect seen in RAP rather than MAP. Reduction rates of BAs Pwere about two folds higher in RAPs than that of MAPs. This shows the advantage of hydrogen incorporation in the package atmosphere on the inhibition of biogenic amine formation, especially in the presence of a high level of CO2. Therefore, RAP may be proposed as a promising technology for limiting the BA formation in fishery products.
Effects of the Incorporation of Hydrogen and Nitrogen Into Milk on the Reducing and Acidification Capacities of Yoghurt Bacteria
(Wiley, 2023) Bulut, Menekse; Alwazeer, Duried; Tunctuerk, Yusuf
The use of gases in different food applications has increased in the last decades. The incorporation of hydrogen into yogurt was reported to improve the organoleptic properties of some dairy products. A study is needed to understand the effect of this application on the behavior of yogurt bacteria during the fermentation stage. The effects of H-2- and N-2-incorporation into milk on the acidification and reducing capacities of Lactobacillus delbrueckii subsp. bulgaricus (LB) and Streptococcus thermophilus (ST) were envisaged. A data acquisition multiparameter interface equipped with pH and redox electrodes was used for continuously measuring and recording values. H-2 increased the acidification capacity of ST (+10%) and the reducing capacity of LB (+13.7%), whereas N-2 increased the acidification capacity of ST (+13.3%) and decreased the reducing capacity of LB (-21.47%) and ST (-18.88%). H-2 increased the coagulation time of LB (+12.96%) and ST (+6.15%). Results could reveal the promotive role of hydrogen on the metabolic activity of yogurt bacteria in single cultures and these bacteria grow better in the presence of hydrogen in milk. These results will allow yogurt manufacturers to better understand the behavior of yogurt bacterial strains when the preparation of gas-incorporated yogurt is envisaged and better control its quality attribute notes.
Fortification of Milk With Plant Extracts Modifies the Acidification and Reducing Capacities of Yoghurt Bacteria
(Wiley, 2020) Alwazeer, Duried; Bulut, Menekse; Tuncturk, Yusuf
The acidification and reducing capacities of yoghurt bacteria were evaluated in different plant extract-enriched milk samples. The milk samples enriched with thyme and grape seed extracts exhibited the highest values of acidification capacity for Lactobacillus delbrueckii subsp. bulgaricus (LB) (0.0065 pH unit/min) and Streptococcus thermophilus (ST) (0.0068 pH unit/min). The highest values of reducing capacity were observed in thyme (-0.98 mV/min), grape (-1.92 mV/min) and green tea (-0.75 mV/min)-enriched samples for LB, ST and mixed culture of LB + ST, respectively. The fortification of yoghurt with plant extracts modified the acidification and reducing activities of starters, thus changing the fermentation time and quality attributes of the product.
Hydrogen Inclusion in Modified Atmosphere Extends the Shelf Life of Chilled Rainbow Trout Fillets
(Central Fisheries Research inst, 2023) Bulut, Menekse; Okutan, Guelistan; Alwazeer, Duried; Boran, Gokhan
Different gas formulations with inclusion of hydrogen were evaluated for extension of shelf life of chilled rainbow trout. A control and four treatment samples were as follows: Control (air), MAP1 (50% CO2 / 50% N2), MAP2 (60% CO2 / 40% N2), RAP1 (50% CO2 / 46% N2 / 4% H2) and RAP2 (60% CO2 / 36% N2 / 4% H2). Samples were stored at +2 & PLUSMN;1 & DEG;C for 15 days and periodically analyzed for changes in their quality. TBARS exceeded consumable limits in control after 5 days while treatment samples were under the limit during storage. Consumable limits for TVB-N were exceeded after 7 days in control while treatment samples remained below the limit. The modified atmosphere was significantly effective in retarding protein degradation although a modest difference was observed due to hydrogen inclusion. Gradually increased microbial counts also confirmed quality loss in control while a rather limited change was observed under a modified atmosphere. Microbial loads of treated samples were under consumable limits until the 10th day, while control reached to limits by just the 3rd day. The incorporation of molecular hydrogen in a modified atmosphere may bring benefits to the seafood industry although further research is needed.
Kekik, Nane, Uçkun, Üzüm Çekirdeği ve Yeşil Çay Çöpü Lifinde Optimum Etanolik Ekstraksiyon Şartlarının ve Fenolik Profillerinin Belirlenmesi
(2020) Tunçtürk, Yusuf; Alwazeer, Duried; Akpolat, Hacer; Bulu, Menekşe; Türkhan, Ayşe
Bu çalışmanın amacı beş bitkinin antioksidan özelliklerini ve farklı etanol oranlarının ektraksiyona etkisini belirlemektir. Kekik, nane, uçkun, üzüm çekirdeği ve yeşil çay çöpü lifinin toplam fenolik madde içeriği (TPC) ve ABTS ve DPPH radikal giderme aktivitesi testleri kullanılarak antioksidan aktiviteleri ölçülmüştür. Bireysel fenolik maddeler ters faz yüksek performanslı sıvı kromotografisi (HPLC) kullanılarak analiz edildi. TPC bitki türü ve çözücü etanol oranına bağlı olarak 2.00±0.27 ile 172.68±0.19 mg GAE g -1 dw arasında değişti. Etanol oranının etkisi farklı bitkiler için değişiklik gösterdi. En yüksek antioksidan aktiviteye sahip ekstraktların HPLC analizleri en yüksek fenolik bileşen konsantrasyonu yeşil çay çöpü lifinde (699.89 mg 100 g-1 dw), en düşük ise nanede (173.67 g 100 g-1 dw) bulundu. Toplam fenolik madde içeriği ve antioksidan aktivite arasında daha önceki çalışmalarda da gösterildiği gibi kayda değer bir korelasyon belirlendi.