GB/T 20570-2015Guidelines for evaluating the storage character of maize (English PDF)

Foreword

This standard was drafted in accordance with GB/T 1.1-2009 given rules. This standard replaces GB/T 20570-2006 "Corn Storage Quality judgment rule." Compared with GB/T 20570-2006, in addition to editorial Modify, mainly technical changes are as follows:

--- Modify the values \u200b\u200bin Table 1 should be stored in the fatty acid index;

--- Modify part of Appendix A, increasing the instrumental method. The standard proposed by the National Food Authority. This standard by the National Grain and Oil Standardization Technical Committee (SAC/TC270) centralized. This standard is drafted by: National Food Authority Standard Quality Center, Chengdu, China Grain Reserves Corporation Grain Storage Sciences The, China Grain Reserves Corporation. Participated in the drafting of this standard. National Food Quality Monitoring Center, Hebei, Inner Mongolia, national food quality monitoring center, Liaoning national food Quality Monitoring Center, the National Food Quality Monitoring Center of Jilin, Heilongjiang national food quality monitoring center, Fujian National Food Quality Monitoring Heart, Guangdong national food quality monitoring center. Drafters of this standard. Long clever, Ho Chao, Zhu light, Mr Fung construction, Jiang Tao, Li Yuan new, Liu flowers, Buchun Hai, Yuan Xiaoping, Tang Jie, Xiao Lirong, Yin Jun, Cui Guohua, Song length right, Songxiu Juan, Zheng Shaohua, Wang Yajun. This standard replaces the standards previously issued as follows:

--- GB/T 20570-2006. Corn storage quality decision rule

1 Scope

China's national rules for judging how well stored maize is holding up. It specifies the terms and definitions for the storage quality of maize, the classification of storage quality, the storage quality indicators, the test methods, the inspection rules and the judging rules, and it applies to evaluating maize stored at safe moisture under proper conditions and to guiding the timely rotation of stored grain. China holds enormous state grain reserves, and the question this standard answers is an operational one with a large price attached: when must a lot be rotated out. Grain does not fail suddenly. It deteriorates continuously in store, and long before it is unfit it stops being suitable for the use it was reserved for - the starch and protein change, the fat begins to hydrolyse and oxidise, and the grain loses its viability and its processing quality while still looking and smelling acceptable. Rotate too early and the reserve is turned over at unnecessary cost; rotate too late and grain intended for food has to be sold as feed. So the standard defines three categories - suitable for storage, tolerable for storage, and not suitable for storage - and fixes the indicators that place a lot in one of them. The central one is the fat acidity value, because maize has a high oil content concentrated in the germ, and hydrolysis of that oil is the most sensitive early measure of deterioration; it rises steadily and measurably long before any sensory change. Alongside it sit the sensory evaluation of the boiled grain and the viscosity, with the test methods and the sampling and judging rules that make a result from one warehouse comparable with another. Issued on 15 May 2015 and in force since 1 June 2015, it replaces GB/T 20570-2006.

This standard specifies the quality of corn stored terms and definitions, quality classification storage, storage quality indicators, test methods, inspection rules and sentence Set rules. This standard applies to the evaluation of the quality of maize stored in safe water and proper storage conditions and timely guidance to store corn rotation.

2 Normative references

The following documents for the application of this document is essential. For dated references, only the dated version suitable for use herein Member. For undated references, the latest edition (including any amendments) applies to this document. Preparation of

GB/T 601 chemical reagent standard titration solution

GB/T 5490-2010 Inspection of grain and general rules

GB 5491 grain and oilseeds testing for sampling, and sample method

GB/T 5492 Inspection of grain and grain, oil color, smell, taste Identification

GB/T 5497 grain, oilseeds test determination of moisture content

GB/T 5507 Inspection of grain and flour thickness determination

GB/T 6682 analytical laboratory use specifications and test methods ( ISO 3696. 1987, MOD)

GB/T 20569 quality rice storage decision rule

GB/T 29405-2012 Inspection of grain and grain products, fatty acid value measuring instrument method

3 Terms and Definitions

GB/T 20569 and defined by the following terms and definitions apply to this document.

3.1 Color color Corn under standard conditions based on color and gloss.

3.2 Odor odor Corn under specified conditions integrated odor.

3.3 Cooking tasting cookingqualityevaluation After corn into corn flour, under specified conditions be made into corn bread, its color, odor, appearance, structure, internal character, taste, etc. Tasting test, the results expressed in taste scores.

3.4 Tasting scores tastingassessmentvalue Wotou tasting sum test the resulting color, odor, appearance, structure, internal character, taste and other rating values.