Chương 3 bien doi hoa sinh trong che bien TP

Chng 3: HểA SINH TRONG CH BIN THC PHM Ni dung: 3.1 S nõu húa phi enzyme 3.1.1 Phn ng Maillard 3.1.2 Caramel húa 3.1.3 S oxi húa acid ascorbic 3.2 Húa sinh sn xut bia 3.2.1 Quỏ trỡnh dch húa, ng húa 3.2.2 Lờn men ru ethylic 3.3 Húa sinh ch bin sa 3.3.1 Sn xut phomat 3.3.2 Sn xut sa chua 3.4 Húa sinh ch bin rau, qu 3.4.1 S nõu húa enzyme 3.4.2 Hp cht pectin 3.1 S nõu húa phi enzyme 3.1.1 Phn ng Maillard Phn ng Maillard (phn ng nõu hoỏ phi enzyme) l hp ca cỏc phn ng gia aminoacid v ng kh nhit tng cao The Maillard reaction is not a single reaction, but a complex series of reactions between amino acids and reducing sugars, usually at increased temperatures Like caramelization, it is a form of non-enzymatic browning French scientist Louis Camille Maillard (18781936) The initial step of the Maillard reaction between glucose and an amino acid (RNH2), in which R is the amino acid side group (from ref 2) Phc hp Amadori S hỡnh thnh HMF v s sp xp li Amadori Formation of HMF and Amadori-rearrangement (from ref 2) Structures of fural and HMF After the Amadori-rearrangement three different main pathways can be distinguished : Dehydratation reactions, Fission, when the short chain hydrolytic products are produced, for example diacetyl and pyruvaldehyde, Strecker degradations with amino acids or they can be condensated to aldols hng phn ng ca hp cht Amadori: S phõn gii (fission) Loi nc (Dehydration) Phõn gii Strecker (Strecker degradation) Cỏc kt qu ca phn ng Maillard: To cỏc cht cú mu nõu ( Melanoidin) cha nit, cú MW v tan nc khỏc To cỏc cht bay hi cú mựi (trong quỏ trỡnh rỏn, nng, quay) To cỏc cht cú v ng cn thit ch bin c phờ, nhng to v l quay tht hoc cỏ To cỏc cht kh mnh (Reductone) - bo v thc phm b oxy hoỏ Lm mt nhiu aminoacid thit yu (Lysine, Cysteine, Methionine) To mt s cht cú kh nng gõy ung th To cỏc hp cht cú th liờn kt chộo vi protein The Maillard Reaction in Foods Produces aromas in heated foods Responsible for colour formation (non-enzymatic browning) Maillard products have antioxidant properties Can cause loss of nutrients Some products may be toxic Cỏc bin i hoỏ sinh th cp quỏ trỡnh chớn ca phomat Bin i cỏc acid bộo Trao i citric acid vi khun lactic Sự thuỷ phân protein chế biến phomat to hng 3.3.2 Sa chua Quy trỡnh ch bin sa chua Lờn men lactic acid Bao gm: 10 phn ng ca quỏ trỡnh ng phõn P. 11: Kh pyruvic acid thnh lactic acid Lactat Dehydrogenase CH3COCOOH + NADH.H+ CH3CHOHCOOH + NAD+ Lactic acid 04/05/17 51 3.4 Húa sinh ch bin rau, qu 3.4.1 S nõu húa enzyme 3.4.2 Các hợp chất pectin Cấu tạo: Là polygalacturonic acid, phần nhóm cacboxil bị methyl hoá Các galacturonic acid liên kết liên kết 1,4 Glucoside o h oh h h o h oh c ooh c ooh cooch3 h h oh o h h o h oh h h oh o h h o h h oh oh n Phân chia: Acid pectic: 30 100 gốc galacturonic acid không bị methyl hoá Acid pectinic: Polygalacturonic acid bị methyl hoá phần Pectin hoà tan: Pectinic acid bị methyl hoá nhiều Pectin không hoà tan: 04/05/17 58 Tớnh cht ca pectin: - To gel vi acid hu c v ng - Trong sn xut nc qu: phõn lp ... 3. 1 Sự nâu hóa phi enzyme 3. 1.1 Phản ứng Maillard 3. 1.2 Caramel hóa 3. 1 .3 Sự oxi hóa acid ascorbic 3. 2 Hóa sinh sản xuất bia 3. 2.1 Quá trình dịch hóa, đường hóa 3. 2.2 Lên men rượu ethylic 3. 3... ethylic 3. 3 Hóa sinh chế biến sữa 3. 3.1 Sản xuất phomat 3. 3.2 Sản xuất sữa chua 3. 4 Hóa sinh chế biến rau, 3. 4.1 Sự nâu hóa enzyme 3. 4.2 Hợp chất pectin 3. 1 Sự nâu hóa phi enzyme 3. 1.1 Phản ứng... hoá Sugar Fructose Galactose Glucose Maltose Sucrose Temperature 110o ( 230 oF) 160 (32 0) 160 (32 0) 180 (35 6) 160 (32 0) 3. 1 .3 Sự oxi hóa acid ascorbic Sự phân giải vitamin C xảy cách: - Điều kiện