Farklı uygulamaların minimal işlem görmüş (fresh - cut) bazı sebzelerin kalitesi üzerine etkileri
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Date
2009
Authors
İncedayı, Bige
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Publisher
Uludağ Üniversitesi
Abstract
Bu çalışmada balkabağı, kereviz ve patates minimal yöntemle (fresh - cut) işlenerek, modifiye atmosfer ortamında paketlenip muhafazaya alınmıştır. Sebzeler, ön işlemler aşamasında tuz, sodyum metabisülfit ve klor çözeltileri ile muamele edilmiş; su ile durulandıktan sonra sitrik asit ile L - sistein çözeltilerine daldırılmış ve santrifüjlendikten sonra çift yönlü gerdirilmiş polipropilen (BOPP) filmle birlikte polipropilen (PP) tabak içerisinde, iki farklı atmosfer koşuluna sahip ortamda paketlenmiştir. Sonuçta, tüm bu uygulamaların, ürünler üzerindeki etkileri saptanmış ve en uygun işleme koşulları belirlenmiştir.Minimal işlem görmüş sebzelerin önemli besin öğelerinden askorbik asit, toplam fenolik madde ve karotenoid madde içeriklerinde depolama boyunca azalmalar görülmüş; bu azalış ön işlemler aşamasında kimyasal muamele görmeden paketlenen tanık örneklerde daha yüksek düzeylerde gerçekleşmiştir. Söz konusu öğeler balkabağında sırasıyla 2.23 - 7.09 mg / 100 g, 232.93 - 490.74 mg GAE /100 g, 99.37 - 251.93 mg / kg; kerevizde 4.59 - 8.08 mg / 100 g, 346.08 - 497.04 mg GAE / 100 g, 11.77 - 51.70 mg / kg; patateste 2.67 - 8.38 mg / 100 g, 165.36 - 283.81 mg GAE / 100 g, 25.26 - 64.21 mg / kg arasında değişmiştir. Genel olarak toplam fenolik madde miktarı ile pozitif korelasyon gösteren antioksidan aktivite oranları balkabağında % 22.39 - 44.09; kerevizde % 55.84 - 93.03; patateste % 13.38 - 25.04 olarak saptanmıştır.Özellikle kereviz ve patateste önemli bir problem olan esmerleşme, kullanılan kimyasallar sayesinde ortalama iki haftaya kadar önlenebilmiştir. Depolama boyunca polifenoloksidaz enzim aktivitesinde görülen farklılıklar % 1 olasılık düzeyinde önemli bulunmuş ve kerevizde 826.77 - 4867.63 U / g; patateste 549.86 - 6931.03 U / g arasında değişim göstermiştir.Depolama süresince solunumla birlikte balkabağında % 0.03 - 0.13; kerevizde % 0.18 - 0.32; patateste % 0.01 - 0.04 oranında ağırlık kaybı meydana gelmiştir. Bu kayıp, azot atmosferinde paketlenen örneklerde karbondioksit ve azot karışımıyla paketlenenlere göre daha yüksek bulunmuştur.Fresh - cut sebzelerin toplam kurumadde ve toplam asit miktarları, depolama boyunca fazla bir değişim göstermemiş olmakla birlikte, sonuçlar arasındaki farklılıklar istatistiki anlamda önemli bulunmuştur (p<0.01).Mikrobiyolojik yönden değerlendirildiğinde, tanık örneklerde kısa süre sonra toplam bakteri sayısında artış görülmüş; koliform bakteri sayısının da ortalama 8. günden itibaren yükselmesiyle, bu ürünler tüketilebilme niteliğini kaybetmiştir. Sitrik asit uygulaması ise, ortalama iki hafta boyunca, ürünleri mikrobiyolojik yönden güvence altına almıştır.Duyusal olarak; L - sistein uygulaması yapılan sebzeler, koku parametresi bakımından % 95 olasılıkla panelistler tarafından red edilmiş; ancak aynı uygulama özellikle kereviz ve patateste esmerleşmeyi yavaşlatarak, renk ve görünüş parametreleri bakımından örneklerin tercih edilmesini sağlamıştır. Sertlik açısından, örnekler arasındaki farklılıkların duyusal olarak hissedilemeyecek kadar az olması, panelistler tarafından etkin bir değerlendirme yapılamamasına neden olmuştur.
In this research, pumpkin, celery and potato were minimally processed and stored after modified atmosphere packaging. The vegetables were treated with NaCl, Na ? metabisulphite and chlorinated, and then rinsed with tap water. After this process, a part of vegetables were treated with citric acid and the other part with L ? cysteine. They were packaged with biaxially oriented polypropylene (BOPP) film and polypropylene (PP) plate under two different modified atmosphere conditions after centrifugation. Effects of all applications and optimum processing parameters were determined.During the storage period, ascorbic acid, total phenolics and total carotenoids content were decreased. More reductions were occurred in blank samples which were not treated with any chemicals. Ascorbic acid, total phenolics and total carotenoids were respectively determined as 2.23 - 7.09 mg / 100 g, 232.93 - 490.74 mg GAE /100 g, 99.37 - 251.93 mg / kg for pumpkin; 4.59 - 8.08 mg / 100 g, 346.08 - 497.04 mg GAE / 100 g, 11.77 - 51.70 mg / kg for celery and 2.67 - 8.38 mg / 100 g, 165.36 - 283.81 mg GAE / 100 g, 25.26 - 64.21 mg / kg for potato. Generally, a positive correlation was found between total phenolics and antioxidant activity and the ratios of antioxidant activity were changed between 22.39 - 44.09 % for pumpkin; 55.84 - 93.03 % for celery and 13.38 - 25.04 % for potato.Browning was an important problem for minimally processed celery and potato and could be prevented approximately for two weeks by chemical applications. During the storage period, there was a significant difference (p <0.01) between polyphenoloxidase activities of the samples which were changed between 826.77 - 4867.63 U / g for celery and 549.86 - 6931.03 U / g for potato.Weight losses of pumpkin, celery and potato occurred by the respiration during the storage were measured as 0.03 - 0.13 %, 0.18 - 0.32 %, 0.01 - 0.04 % respectively. This loses in the samples packaged with only nitrogen gas was higher than the samples packaged with both carbon dioxide and nitrogen.Slight changes were observed in the total dry matter and total acidity values of minimally processed vegetables; but a significant difference was found statistically for these parameters (p<0.01).In blank samples, total aerobic and mesophilic bacteria counts increased after a short time and these samples were lost their consumption quality by the increase of coliform bacteria counts also. Furthermore, the microbiological quality of the vegetables was preserved for two weeks with the citric acid application.When the results of sensory analysis were evaluated it was concluded that L ? cysteine application was rejected by the panelists by 95 % probability because of its unliked odor. But at the same time, this application was prevented enzymatic browning of the celery and potato and provided preference in terms of their color and appearance. Because of so slight texture differences in the samples, they were not distinguished by the panelists.
In this research, pumpkin, celery and potato were minimally processed and stored after modified atmosphere packaging. The vegetables were treated with NaCl, Na ? metabisulphite and chlorinated, and then rinsed with tap water. After this process, a part of vegetables were treated with citric acid and the other part with L ? cysteine. They were packaged with biaxially oriented polypropylene (BOPP) film and polypropylene (PP) plate under two different modified atmosphere conditions after centrifugation. Effects of all applications and optimum processing parameters were determined.During the storage period, ascorbic acid, total phenolics and total carotenoids content were decreased. More reductions were occurred in blank samples which were not treated with any chemicals. Ascorbic acid, total phenolics and total carotenoids were respectively determined as 2.23 - 7.09 mg / 100 g, 232.93 - 490.74 mg GAE /100 g, 99.37 - 251.93 mg / kg for pumpkin; 4.59 - 8.08 mg / 100 g, 346.08 - 497.04 mg GAE / 100 g, 11.77 - 51.70 mg / kg for celery and 2.67 - 8.38 mg / 100 g, 165.36 - 283.81 mg GAE / 100 g, 25.26 - 64.21 mg / kg for potato. Generally, a positive correlation was found between total phenolics and antioxidant activity and the ratios of antioxidant activity were changed between 22.39 - 44.09 % for pumpkin; 55.84 - 93.03 % for celery and 13.38 - 25.04 % for potato.Browning was an important problem for minimally processed celery and potato and could be prevented approximately for two weeks by chemical applications. During the storage period, there was a significant difference (p <0.01) between polyphenoloxidase activities of the samples which were changed between 826.77 - 4867.63 U / g for celery and 549.86 - 6931.03 U / g for potato.Weight losses of pumpkin, celery and potato occurred by the respiration during the storage were measured as 0.03 - 0.13 %, 0.18 - 0.32 %, 0.01 - 0.04 % respectively. This loses in the samples packaged with only nitrogen gas was higher than the samples packaged with both carbon dioxide and nitrogen.Slight changes were observed in the total dry matter and total acidity values of minimally processed vegetables; but a significant difference was found statistically for these parameters (p<0.01).In blank samples, total aerobic and mesophilic bacteria counts increased after a short time and these samples were lost their consumption quality by the increase of coliform bacteria counts also. Furthermore, the microbiological quality of the vegetables was preserved for two weeks with the citric acid application.When the results of sensory analysis were evaluated it was concluded that L ? cysteine application was rejected by the panelists by 95 % probability because of its unliked odor. But at the same time, this application was prevented enzymatic browning of the celery and potato and provided preference in terms of their color and appearance. Because of so slight texture differences in the samples, they were not distinguished by the panelists.
Description
Keywords
Sebzeler, Vegetables
Citation
İncedayı, B. (2009). Farklı uygulamaların minimal işlem görmüş (fresh - cut) bazı sebzelerin kalitesi üzerine etkileri. Yayınlanmamış doktora tezi. Uludağ Üniversitesi Fen Bilimleri Enstitüsü.