Beyaz peynirlerde nitrat ve nitrit tayin yöntemleri ve olgunlaşma süresince nitrat ve nitrit miktarında meydana gelen değişmeler
Küçük Resim Yok
Tarih
1995
Yazarlar
Dergi Başlığı
Dergi ISSN
Cilt Başlığı
Yayıncı
Ege Üniversitesi
Erişim Hakkı
info:eu-repo/semantics/openAccess
Özet
Bu çalışmada; öncelikle beyaz peynirlerde nitrat ve nitrit miktarını tespit amacıyla 2 farklı analiz yöntemi ile çalışılmıştır. Yöntem tespit çalışmalarının sonucunda; kadmiyum kolon yönteminin geri kazanım oranı, gaz kromatografisi yöntemine göre daha yüksek bulunmuştur. Ayrıca kadmiyum kolon yönteminde kolonun indirgeme kapasitesi kontrol edilebilmekte ve test örneğinin analize hazırlanması daha pratik olmaktadır. Bu nedenle çalışmadaki analizlerin tümü kadmiyum kolon yöntemi kullanılarak yapılmıştır. Deneme beyaz peynirlerinin üretim aşamasında süt pastörize edilip, soğutulduktan sonra 4 eşit bölüme ayrılmış,* olgunlaşma aşamasından sonra bir bölümü kontrol amacıyla KNO3 ilave edilmeden, diğer 3 bölümü sırasıyla sütlere 15 g KNO3/ 100 1 süt, 30 g KNO3/ 100 1 süt ve 50 g KNO3 / 10Q İt süt ilave edilerek beyaz peynire işlenmiştir. Deneme beyaz peynirlerinde l.,10., 25. ve 50. günlerde yapılan analizlerde ortaya çıkan sonuçlar şöyle olmuştur: a) Nitrat ilave edilerek üretilen tüm peynir örneklerinde depolama süresince nitrat miktarlarında ilk üç hafta hızlı, daha sonra yavaş oranda bir indirgenme meydana gelmiştir. b) Deneme süresince; olgunlaşma indeksi değerleri, bir artış göstermiştir. c) Nitrat ilavesi ile üretilmiş peynirlerdeki nitrit oranları; salamura sonrasında, ilave edilen miktara paralel olarak yüksek bulunmuş, fakat bunu takip eden ilk 10 gün içerisinde nitrit miktarlarında hızlı bozunmalar tespit edilmiştir. d) Tüm peynir örneklerinde asitlik olgunlaşma süresince artış göstermiştir. Asitlik değerleri; nitrat ilavesi ile üretilmiş peynirlerde 50. günde kontrol peynirlerine göre daha yüksek bulunmuştur. Ayrıca yine 50. günde nitrat ilaveli peynirlerde pH değerlerinin daha düşük olduğu görülmüştür. Bahar döneminde piyasadan temin edilen 14 adet farklı peynir örneğinden sadece 1 peynir örneğinde 52 mg/kg nitrat olduğu; yaz döneminde piyasadan temin edilen 16 adet peynir örneğinden ise 3 tanesinde (% 19) 57.04, 53.11, 63.23 mg/kg oranında nitrat ve 1.089, 1.255, 1.089 mg/kg oranında nitrit olduğu belirlenmiştir. 73
In this study; firstly in order to determine the nitrate and nitrite content of white cheeses, two analysis methods were tried. As a result, it was found that the recovery ratio of cadmium column reduction method was higher than gas chromatographic method. Furthermore in "Cadmium Column Reduction" method, reducing capacity of column can be controlled and preparing test portion for analysis is more practical. For this reason all the analysis in this stttdy was done by cadmium column method. At the production stage; the raw milk was pasteurized, cooled and divided into 4 parts. After incubation period; 0 g/100 1 milk, 15 g KNO3/IOO 1 milk; 30 g KNO3/IOO 1 milk and 50 g KNO3/IOO 1 milk were added to the each part and produced white cheeses. The results obtained from this research on the 1st. 10th, 2 5* & "ami on 50*1» days can be written as follows: a) Nitrate reduction was observed for all cheeses during storage which were produced by nitrate addition. But reductions were very rapid in the first 3 weeks and continued until the end of the storage period with a slower rate. b) Matxiration indexes of cheeses were increased during the storage period. d) Nitrite contents of cheeses which were produced by nitrate additions parallel with nitrate contents, were very high especially after brining. In the first ten days nitrite was decomposed very rapidly. e) Acidity increased normally for all cheeses. But the cheeses which were produced by nitrate addition had higher acidity on the 50th day. pH values decreased after 50th days in cheeses which were produced by nitrate addition g) In the spring period, only 1 of the 14 cheese samples from markets contained nitrate about 52 mg/kg. But in summer period 3 of the 16 cheese samples contained high contents (57.04, 53.11, 63.23 mg/kg) of nitrate and (1.089, 1.255 and 1.089 mg/ kg) nitrite. Consequently, in summer period 19 % of white cheeses contained high levels of nitrate and nitrite. 74
In this study; firstly in order to determine the nitrate and nitrite content of white cheeses, two analysis methods were tried. As a result, it was found that the recovery ratio of cadmium column reduction method was higher than gas chromatographic method. Furthermore in "Cadmium Column Reduction" method, reducing capacity of column can be controlled and preparing test portion for analysis is more practical. For this reason all the analysis in this stttdy was done by cadmium column method. At the production stage; the raw milk was pasteurized, cooled and divided into 4 parts. After incubation period; 0 g/100 1 milk, 15 g KNO3/IOO 1 milk; 30 g KNO3/IOO 1 milk and 50 g KNO3/IOO 1 milk were added to the each part and produced white cheeses. The results obtained from this research on the 1st. 10th, 2 5* & "ami on 50*1» days can be written as follows: a) Nitrate reduction was observed for all cheeses during storage which were produced by nitrate addition. But reductions were very rapid in the first 3 weeks and continued until the end of the storage period with a slower rate. b) Matxiration indexes of cheeses were increased during the storage period. d) Nitrite contents of cheeses which were produced by nitrate additions parallel with nitrate contents, were very high especially after brining. In the first ten days nitrite was decomposed very rapidly. e) Acidity increased normally for all cheeses. But the cheeses which were produced by nitrate addition had higher acidity on the 50th day. pH values decreased after 50th days in cheeses which were produced by nitrate addition g) In the spring period, only 1 of the 14 cheese samples from markets contained nitrate about 52 mg/kg. But in summer period 3 of the 16 cheese samples contained high contents (57.04, 53.11, 63.23 mg/kg) of nitrate and (1.089, 1.255 and 1.089 mg/ kg) nitrite. Consequently, in summer period 19 % of white cheeses contained high levels of nitrate and nitrite. 74
Açıklama
Anahtar Kelimeler
Gıda Mühendisliği, Food Engineering, Beyaz peynir, White cheese, Nitratlar, Nitrates, Nitritler, Nitrites
