肉制品中氧化稳定性检测方案(氧化分析仪)

APPLICATION NOTEF&F-0-001-2015/A1 OXIDATION STABILITY OF MEAT Oxidation Stability of Meat Reference： EURACHEM GUIDELINES Tested with VELP Scientifica OXITEST Oxidation Stability Reactor (Code F30900248) Introduction Meat is one of the most ancient food in human diet， since prehistoric times， when first men hunted wild animals foreating them. Over the centuries， thanks to the civilization， the domestication of animals was allowed (such as chickens，sheep， fish， seafood， pigs and cattle) and nowadays， the meat production is on an industrial scale. Meat is very high in protein and low in carbohydrates， but fat content can vary widely depending on the species andbreed of animal， the anatomical part of the body and its cooking. Thanks to the bacteria that find a nutrient rich substrate， meat is a highly perishable product. Among the alterations， thelipid oxidation results in “off flavor". To preserve meat， in order to be stored and consumed， tenderness， juiciness， flavoror color are protect using additives. Oxidation Stability in Food One of the most important quality alteration of food is due to oxygen absorption by the unsaturated fatty acids， free oresterified. The auto-oxidation of fats is a chemical reaction promoted by oxygen， light， high temperatures， metal tracesand， sometimes， enzymes. OXITEST can determine the oxidation stability of various sample types， without the need for preliminary fat separation. OXITEST Principle OXITEST speeds up the oxidation process because of the two accelerating factors， temperature and oxygen pressure，according to the most common applications. The instrument measures the absolute pressure change inside the two chambers， monitoring the oxygen uptake byreactive components in the sample and automatically generates an IP value. IP Definition： IP stands for Induction Period and it is the time required to reach the starting point of oxidation， corresponding to either alevel of detectable rancidity or a sudden change in the rate of oxidation. The longer the Induction Period， the higher the stabilityagainst oxidation over time. Sample Meat with natural antioxidant Type 1 (Formula F1)Fat labeled value： 30g / 100g of meat Meat with natural antioxidant Type 2 (Formula F2) Equipment and Chemicals ●Analytical balance， 3 decimals●Silicone grease●· Grinder●· Oxygen， purity grade 5.0 Sample Preparation Store the samples at room temperature. Grind meat to a suitable finesse and put 10 grams of homogeneous sample directly on the surface of the titaniumsample holder， by using a spatula. In each reaction chamber (A and B)， place 2 spacer and 1 sample holders containing the sample for a total of 10 g ofmeat in each oxidation chamber. Analysis Procedure Grease the O-rings with silicon grease and set them in their position. Close the chambers with the titanium covers andturn the discharge valves in open position. Set the following conditions on the OXISoftTM software： Temperature： 80 °C Oxygen Pressure： 6 bars When the temperature set is reached inside the chambers， close the discharge valves and start loading oxygen.Data acquisition is automatically started by the software. Typical Results on Meat Each meat sample has been monitored two times. At the end of the oxidation tests， the IP of every run is calculated bythe software OXISoftM. It is possible to elaborate the oxidation curves obtained for each kind of meat. Sample Weight (g) Set Point (bars) Set Point (°C) IP (hh：mm) Line Meat F1 10.000 6.00 80.0 7：32 Meat F1 10.000 6.00 80.0 7：53 Meat F2 10.000 6.00 80.0 5：29 Meat F2 10.000 6.00 80.0 5：33 Formula Comparison With OXISoft M， it is also possible to easily compare the obtained IP values， of different formulations but tested at thesame condition， and identify the most stable one. VELP Scientifica， Italy Tel： +39 039628811 Fax： +39 0396288120 www.velp.com Conclusion The results obtained by OXISoftTM and the formula comparison function clearly discriminate the meat's resistance tooxidation， although the total fats percentage of their formulations is very similar. Meat F1 have a longer IP value， hence a higher oxidation stability. Meat F2 results significantly less stable againstoxidation. This is related to the different effect of different natural antioxidants added Benefits of OXITEST are： Test is made directly on the whole sample No need for preliminary fat separation of the sample Resistant titanium chamber Time saving analysis， if compared to the traditional methods ● Especially designed for R&D， Product Development and Quality Control labs e Many investigations available through the software OXISoftTM： 1. Repeatability test： a series of tests run on the same sample or standard to verify its IP period， to calculateaccuracy and repeatability of the data 2. Freshness test： to verify the quality of different lots， for example of the same raw material， and compare them 3. Formula comparison： to identify the most stable formula of a finished product， under the same conditions 4. Packaging comparison： for testing which packaging maintains the product in the freshest condition 5. IP during ageing： to obtain a graph of the decrease of the product IP during the shelf-life period 6. Estimated shelf life： to have a prediction of oxidation stability during the shelf life. Copyright C VELP Scientifica. All rights reserved.No part of this publication may be reproduced or transmitted in any form or for any purpose without the express permission of VELP.VELP Scientifica， Italy Tel：+ Fax： + www.velp.com