Method for measuring fat content of donkey-hide gelatin cake products

Abstract

The invention discloses a method for measuring the fat content of donkey-hide gelatin cake products. The method comprises the following steps that: a to-be-detected donkey-hide gelatin cake product isfrozen for more than 4 hours under temperature of -15 DEG C to -20 DEG C, and the frozen to-be-detected donkey-hide gelatin cake product is crushed, and the crushed to-be-detected donkey-hide gelatincake product is uniformly mixed so as to be used later; a sample is weighed and transferred into a conical flask, water is added into the conical flask, and an obtained mixture is subjected to ultrasonic treatment; anhydrous ether is added, after shaking and vibration are performed, petroleum ether is added, shaking and vibration are performed again, the stopper and bottle neck of the conical bottle are washed with a mixed solvent of petroleum ether and diethyl ether, and the conical bottle stands still, and then a supernate is sucked out and transferred into a fat collecting bottle, and theabove process is repeated twice; and the fat collecting bottle is arranged above a boiling water bath until the supernate in the fat collecting bottle is evaporated to be dried, the fat collecting bottle is dried, the fat collecting bottle is taken out and is cooled in a dryer, and the fat collecting bottle is weighed, the above operation is repeated until the weight of the fat collecting bottle is constant, and the fat content in the sample is calculated. According to the method disclosed by the invention, the preparation problem of the donkey-hide gelatin cake product sample is solved; organic solvents such as concentrated hydrochloric acid and ethanol are not used; heating and condensation treatment are not needed; inspection work can be completed by 1. 5h; inspection cost is reduced; the use of toxic reagents is suppressed; and the efficiency of an experiment is greatly improved.

Description

technical field [0001] The invention relates to the field of determination of fat content in food testing, in particular to a method for determining the fat content of donkey-hide gelatin cake products. Background technique [0002] Donkey-hide gelatin cake products are derivatives of donkey-hide gelatin, which are very local in Shandong. These products are made of donkey-hide gelatin, walnut kernels, black sesame, red dates, wolfberry or other common food raw materials that can be used in food, and add rock sugar, rice wine and other auxiliary materials. It is made through raw material processing, batching, boiling, cooling, slicing, packaging and other processing techniques. The salient features of this type of product that are different from other foods are: (1) Containing donkey-hide gelatin raw materials with high viscosity, the melted donkey-hide gelatin sticks / wraps together with raw materials such as walnut kernels and sesame seeds during processing, and the product ...

AI Technical Summary

Problems solved by technology

For the detection of fat in donkey-hide gelatin cake, the defects of the above-mentioned technology mainly include the following five aspects: (1) The sample preparation method involved in the relevant domestic and foreign standards cannot prepare the sample into an experimental sample with good uniformity and representativeness, and because of Sesame granules are small, and most of the sesame granules in the samples prepared according to existing standards are completely wrapped by donkey-hide gelatin cakes, resulting in the inability to effectively extract the fat in sesame seeds; And starch sugar raw materials, carbohydrates and protein raw materials will undergo carbonization reaction during the acid hydrolysis extraction process, and the carbonization reaction products will be extracted during the extraction process, resulting in high fat determination results

(3) Due to the high viscosity of donkey-hide gelatin, rock sugar and starch sugar raw materials, if the Soxhlet extraction method is used for determination, the viscosity of donkey-hide gelatin and sugar substances will further increase during the heating and extraction process, and walnut kernels and sesame seeds, etc. Wrapping, so that the extraction solvent cannot fully contact walnut kernels, sesame seeds, etc. for extraction, resulting in the ineffective extraction of fat

(4) Alkaline hydrolysis fat determination method is only applicable to the determination of fat in dairy products. This method uses alkaline solution to destroy the colloidal system of dairy products to free the fat. The fat in donkey-hide gelatin cake is mainly provided by walnut kernels and sesame seeds, which is not suitable for Donkey-hide gelatin special food

(5) Both the acid hydrolysis method and the Soxhlet extraction method have the characteristics of relatively long experimental period, high energy consumption, and large consumption of precursor reagents and organic reagents

In summary, due to the complex matrix of donkey-hide gelatin cake products and the inability of the existing standard sample preparation and detection techniques to accurately detect the fat of donkey-hide gelatin cake samples, a method for sample preparation and fat extraction suitable for donkey-hide gelatin cake products was developed. It is of great significance to meet the requirements of accurate determination of fat and improve the quality control level of products

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