Reducing sugars must have free carbonyl ie glucose galactose fructose

Reducing sugars must have free carbonyl ie glucose

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Reducing sugars: must have free-carbonyl i.e.- glucose, galactose, fructose PROCESSING AFFECTS DIGESTIBILITY - Processing can affect digestibility in humans (more processing is worse for GI tract). Digestibility of proteins, not overall digestibility Digestibility Wheat Whole ground bread White bread Bfast cereal 1 Bfast cereal 2 69 80 65 45 Corn Steamed corn meal Bfast cereal 68 50 Rice
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SFLORES_2/3/2014 25 Polished steamed rice Bfast cereal 78 61 Oats Cooked cereal (oatmeal) Bfast cereal 72 59 o This tells us that the more highly processed, the worse it is for digestibility in GI tract ANTI-NUTRITION FACTORS - There are other anti-nutritional factors that influence protein digestibility, D and A 1. Protein and AA derivatives Trypsin inhibitors Chymotrypsin inhibitors Hemoglutin Maillard reaction products Lathyrogens 2. Glycosides Goitrogens Cyanogens- CN shuts down electron transport Vicines 3. Miscellaneous Tannins Phytates Acrylamides Metal-binding factors Anti-vitamin factors TRYPSIN INHIBITORS - Soy bean was the first report of anti-nutritional factors o Had to be heated to allow growth o Raw soy has a trypsin inhibitor that binds to trypsin Pancreatic hypertrophy occurs (enlargement of pancreatic cells) Can lead to cancer- if hypertrophy lasts long enough Only certain type of heat will destroy trypsin inhibitor in soy Tis OVERCOME BY S-CONTAINING AAs - If soy protein is of low quality or isn’t digested is well, animal will grow slower o Study looked at protein efficiency ratio (PER): tells us how fast an animal grows Growth (PER) g/d Raw soy 1.33 Moist-heated soy 2.62 Raw soy + 0.6% Met 2.42
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SFLORES_2/3/2014 26 o Could overcome growth suppression of raw soy by adding Met (but not completely overcome b/c of other anti-nutritional factors present) § Can overcome growth suppression from raw soy by feeding S-containing AAs o Mechanism: Lack of enzymes = a lot of undigested proteins hitting the gut wall & stimulating CCK CCK release tells the pancreas to keep putting out enzymes (pancreatic enzymes rich in S-containing AAs) The more enzymes put out, the more that gets bound to TI - This depletes the body of S -AAs; § can t carry out normal protein - Irv Lener did a study where he collected human pancreatic juice and added TI to it & then put it back into gut o 2-3x in output of pancreatic juice § Human pancreatic juices are susceptible to TIs and will put out more juice EFFECT OF TI ON PANCREAS - Another study tested if raw soy could have an effect on the pancreas Pancreas size (% total bw) Does raw soy (TI) lead to pancreas size? Mouse 0.7 Yes Rat 0.6 Yes Chicken 0.5 Yes Guinea Pig 0.3 Yes Dog 0.22 No Pig 0.11 No Human 0.10 n/a Calf 0.07 No o § animal size = pancreatic weight (negative correlation) - Moist heat denatures trypsin inhibitors but it has to be for a certain amount of time - TI activity in certain food products o Should be around zero if processed to its fullest extent to denature or detoxify the TI TI Activity (units/mg) TI activity (mg/g protein) Raw soy flour 99 Soy infant formula 1-15
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  • Spring '14
  • Knutson,MitchellD
  • Trp

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