| dc.contributor.advisor | Topcu, Ali | |
| dc.contributor.author | Ghavam, reihaneh | |
| dc.date.accessioned | 2018-01-03T07:21:06Z | |
| dc.date.available | 2018-01-03T07:21:06Z | |
| dc.date.issued | 2017 | |
| dc.date.submitted | 2017-12-08 | |
| dc.identifier.uri | http://hdl.handle.net/11655/4136 | |
| dc.description.abstract | In this study, utilization of camel chymosin in the production of reduced fat ultrafiltrated (UF) white cheese and its effects on the cheese quality was investigated during the ripening period. Animal-calf rennet, fermentation-produced calf chymosin, fermentation-produced camel chymosin and microbial coagulant from Rhizomucor miehei were used in the production of reduced-fat UF white cheeses. The cheese samples were stored at 6-8 ºC, and chemical, biochemical, textural and sensory properties were analysed at 7., 30., 60.,90., and 120 days of ripening.
The composition and pH between the cheeses were almost similar. The results indicated that the higher cheese yield was obtained with microbial coagulant, but it was statistically insignificant. The primary and secondary proteolysis were the lowest in cheeses made with camel chymosin. However, lower proteolysis was also observed in cheeses made with microbial coagulant than other cheeses during ripening (P<0.05). Those results were supported by urea-PAGE and HPLC analysis.
In addition, utilization of camel chymosin had a considerable impact on the textural profile of cheeses (P<0.05). It was found that hardness was higher than other cheeses. But, this affected sensorial scores as to be body and texture negatively. The sensory analysis also indicated that utilization of camel chymosin and microbial coagulant had a positive effect on total acceptability in UF cheeses without causing bitterness. However, the bitterness was determined in other cheeses. | tr_TR |
| dc.description.tableofcontents | ABSTRACT i
ÖZET iii
ACKNOWLEDGEMENT v
TABLE OF CONTENTS vi
TABLES ix
FIGURES x
SYMBOLS AND ABBREVIATIONS xi
1. INTRODUCTION 1
2. LITERATURE REVIEW 4
2.1 Enzymatic Coagulation of Milk 4
2.2 Membrane Technology 6
2.3 Types of Membrane Separation 7
2.3.1 Reverse osmosis (RO) 7
2.3.2 Microfiltration (MF) 7
2.3.3 Nanofiltration (NF) 7
2.3.4 Ultrafiltration (UF) 8
2.4 Characteristics of Cheese Manufactured by UF Processes 11
2.5 Types of Rennet and Coagulants 11
2.5.1 Animal rennet and coagulants 12
2.5.2 Microbial coagulants 14
2.5.3 Vegetable coagulants 15
2.5.4 Fermentation produced chymosin 15
2.6 Camel Chymosin 15
2.7 Production of Enzymes 17
2.8 Rennet Activity 21
2.9 Cheese Ripening 23
2.9.1 Metabolism of residual lactose, lactate and citrate 23
2.9.2 Proteolysis 25
2.9.3 Lipolysis 29
2.10 Low Fat Cheeses 29
2.11 Application of Rennet and Coagulants 33
3. MATERIAL AND METHOD 36
3.1 Material 36
3.2 Method 38
3.2.1 Physicochemical and chemical analyses in cheeses 38
3.2.1.1 Dry matter analysis 38
3.2.1.2 pH determination 38
3.2.1.3 Fat analysis 38
3.2.1.4 Salt determination 38
3.2.1.5 Protein analysis 38
3.2.2 Yield calculation 38
3.2.3 Assessment of proteolysis 38
3.2.3.1 Determination of water-soluble nitrogen (WSN) 38
3.2.3.2 Soluble nitrogen analysis in 12% trichloroacetic acid (TCA) 39
3.2.3.3 Determination of total free amino acid 39
3.2.3.4 Polyacrylamide gel electrophoresis (Urea-PAGE) 40
3.2.3.5 Determination of proteolysis in cheese samples by RP-HPLC 40
3.2.4 Texture profile analysis 41
3.2.5 Sensory evaluations 41
3.2.6 Statistical evaluation 41
4. RESULTS AND DISCUSSION 42
4.1 Physicochemical and Chemical Analysis Results 42
4.2 Yield (%) of the Cheese Samples 44
4.3 Assessment of Proteolysis 45
4.3.1 Analysis of water soluble nitrogen fractions (WSN) 45
4.3.2 Analysis of 12% trichloroacetic acid soluble nitrogen fractions (TCA-SN) 46
4.3.3 Analysis of total free amino acids 47
4.3.4 Results of Urea-PAGE electrophoresis 48
4.3.5 Results of RP-HPLC analysis 51
4.4 Results of Texture Analysis 55
4.5 Results of Sensory Evaluation 56
5. CONCLUSION 59
REFERENCES 61 | tr_TR |
| dc.language.iso | en | tr_TR |
| dc.publisher | Fen Bilimleri Enstitüsü | tr_TR |
| dc.rights | info:eu-repo/semantics/openAccess | tr_TR |
| dc.subject | ultrafiltrated white cheese | |
| dc.subject | reduced fat | |
| dc.subject | rennet | |
| dc.subject | camel chymosin | |
| dc.subject | bitterness | |
| dc.subject | proteolysis | |
| dc.title | Utilization Of Camel Chymosin In The Production Of Reduced Fat Ultrafiltrated White Cheese And Its Effect On Cheese Quality | tr_TR |
| dc.type | info:eu-repo/semantics/masterThesis | tr_TR |
| dc.description.ozet | Bu çalışmada, yağı azaltılmış ultrafiltre (UF) beyaz peynir üretiminde deve kimozini kullanımı ve bunun peynir kalitesi üzerine etkileri raf ömrü süresince tespit edilmişti. Yağı azaltılmış UF beyaz peynirlerin üretiminde, hayvansal-buzağı renneti, fermente buzağı kimozini, fermente deve kimozini ve Rhizomucor miehei' den elde edilen mikrobiyal koagülant kullanılmıştır. Üretimi gerçekleştirilen peynirler 6-8 °C de depolanmış ve olgunlaşmanın 7., 30., 60.,90., ve 120. günlerinde, kimyasal, biyokimyasal, tekstürel ve duyusal özellikleri araştırılmıştır.
Peynirlerin bileşim ve pH değerleri birbirine yakın bulunmuştur. Elde edilen sonuçlara göre, mikrobiyal koagulant kullanımı peynirlerde verimi artırmıştır, fakat bu istatistiksel açıdan önemli bulunmamıştır. Birincil ve ikincil proteoliz, deve kimozini kullanılarak üretilen peynirlerde en düşük bulunmuştur. Bununla beraber, mikrobial koagülant ile üretilmiş peynirlerde de olgunlaşma süresince diğer peynirlerden daha düşük proteoliz gözlenmiştir (P<0,05). Bu sonuçlar üre-PAGE ve HPLC analizleri ile desteklenmiştir.
Ayrıca, deve kimozini kullanımı peynirlerin tekstürel profilini önemli düzeyde etkilemiştir (P<0,05). Diğer peynirler ile karşılaştırıldığında, sertlik değerleri yüksek bulunmuştur. Fakat, bu durum duyusal açıdan tekstür ve yapı skorlarını olumsuz etkilemiştir. Ayrıca, duyusal analizler, deve kimozini ve mikrobiyal koagülant kullanımının UF peynirlerinde acılaşmaya neden olmadan toplam kabul edilebilirlik değerlerine pozitif etki yaptığını göstermiştir. Bununla beraber, diğer peynirlerde acılaşma tespit edilmiştir. | tr_TR |
| dc.contributor.department | Gıda Mühendisliği | tr_TR |
| dc.contributor.authorID | 10172430 | tr_TR |
