【作者】 刘伟；

【导师】 李晓玺； 李志勇；

【作者基本信息】 华南理工大学 ， 食品工程（专业学位）， 2022， 硕士

【摘要】 广式烘焙食品因其选料考究、口味丰富和外形精美等特点而广受消费者青睐,但也因其含有肉类及高糖分等特点而使其在热加工过程中不可避免地导致杂环胺类化合物（HAs）等一系列伴生危害物的生成。因此,开发既能抑制内源性危害物的生成同时又可以保持食品品质的广式烘焙食品加工工艺对于目前的广式烘焙食品行业而言仍是一项巨大的挑战,其首先便受限于该类食品中痕量杂环胺高效富集和定量检测。本文针对上述问题,基于共价有机框架（COFs）材料微/介孔结构、易于化学修饰及结合目标物能力强等特性,选择酮烯胺型COFs并对其进行功能化修饰,建立用于快速、精确检测广式烘焙食品中HAs的新方法,并以所建立的检测方法,系统探究了糖醇替代方式对广式烘焙食品中多元危害物生成的影响规律,明晰了食品组分改变后广式焙烤食品的质构和风味等品质的变化情况。本研究对于广式烘焙食品行业的健康发展以及高品质的烘焙食品开发具有重要的意义。选择COFs作为固体吸附剂富集广式烘焙食品中超痕量的HAs,需要其与HAs之间有着较强的相互作用。基于杂环胺分子中含有的环外氨基,选择TpBD-COF材料作为基础材料,通过自下而上法和后修饰法两种策略对TpBD-COF进行羧基化修饰,分别得到CTpBD-COF和TpBD-COOH-COF两种不同结构的新材料。系统探究了三种COFs材料的结晶性、官能团、表面特性及其对16种HAs的吸附动力学和等温吸附行为,结合材料结构的变化,揭示了材料的吸附性能和结构的关系,最终获得了性能优异的吸附剂材料。结果显示,三种材料均生成了酮烯胺结构,得到了相应的有机框架材料。引入羧基后,材料的结晶程度明显降低,而结晶特性直接影响了材料孔道的形成,同时由于羧基的占位效应,导致TpBD-COOH和CTpBD的比表面积由未修饰羧基前的161 m²·g^-1分别下降到96 m²·g^-1和18 m²·g^-1。羧基修饰后,材料的亲水性增强。后修饰法得到的TpBD-COOH-COF具有更强的吸附能力,等温吸附模型拟合得到的最大吸附量为297.62～4438.35μg·g^-1,说明材料对HAs的吸附性是材料的孔道结构和羧基共同作用的结果。以获得的TpBD-COOH为吸附材料,采用聚丙烯微孔滤膜制备出膜保护微固相萃取装置,对萃取过程中的吸附条件和解吸条件进行优化,最终结合HPLC-MS建立了快速、准确检测广式烘焙食品中HAs的方法。该方法对广式烘焙食品中16种HAs的最低检测限为0.037～1.387μg·kg^-1,最小定量限为0.093～3.413μg·kg^-1;在加标量为5、20、100μg·kg^-1的广式烘焙食品中的回收率分别为81.9～112.0%,76.6～118.7%,72.6～118.5%;在加标量为5、20、100μg·kg^-1的广式烘焙食品中的日内和日间相对标准偏差均小于10%,具有良好的稳定性;同目前文献报道的检测方法相比,此方法检测的HAs种类更多,灵敏度和准确度都较高,并且适用范围更广,是一种应用性较强的检测方法。以建立的HAs富集检测方法为基础,探究了糖醇的种类和替代量对广式烘焙食品中HAs和丙烯酰胺（AA）的抑制作用。同时,考察了糖醇种类和替代量对食品质构和味觉等品质指标的影响。结果表明,赤藓糖醇对月饼、鸡仔饼和杏仁饼中HAs和AA的总生成量的抑制效果最好。三种烘焙食品中50%的蔗糖被赤藓糖醇替代后,月饼、鸡仔饼和杏仁饼中两类危害物的总生成量分别下降了72.1%、57.0%和68.6%。赤藓糖醇对三种食品的质构性质影响较小。而随着赤藓糖醇替代量的不断提高,对三种广式烘焙食品中的危害物总量的抑制效果也更加显著,但对其质构性质没有显著影响。糖醇替代蔗糖后,原有食品的味觉品质发生了一定的变化,但可通过控制其在三种广式烘焙食品中的替代量,可以减少对味觉品质的影响。本文通过对TpBD-COF进行羧基化修饰,获得了对HAs具有优良吸附特性的TpBD-COOH-COF材料,将其作为吸附剂制备出膜保护微固相萃取装置,并结合HPLC-MS建立了快速、准确检测广式烘焙食品中HAs的方法。以该方法为基础,探究出赤藓糖醇对月饼、鸡仔饼和杏仁饼中HAs和AA的总生成量具有显著的抑制效果。通过调整替代量,可以控制其对危害物的抑制效果,并同时保证广式烘焙食品保持良好的质构性质和味觉品质。研究结果对高品质健康广式烘焙食品的创制提供了理论依据。更多还原

【Abstract】 Cantonese bakery is widely favored by consumers because of its exquisite materials,rich taste and delicate appearance.But because of its high content of sugar and animal meat,it inevitably leads to the generation of a series of associated hazards such as heterocyclic amine compounds（HAs）during thermal processing.Therefore,it is still a huge challenge for the current Cantonese bakery industry to develop a processing technology that can both inhibit the generation of endogenous hazards and maintain food quality.Above all,it is limited by the efficient enrichment and quantitative detection of trace heterocyclic amines in such food.In order to solve the above problems,based on the characteristics of covalent organic framework（COFs）,such as micro/mesoporous structure,easy chemical modification and strong binding ability,ketene amine COFs was selected as the alternative adsorbent material and functionalized,thus a new method for rapid and accurate detection of HAs in Cantonese bakery was established.Finally,the established detection method was used to systematically explore the effect of sugar alcohol substitution on the formation of multiple harmful substances and the changes of quality parameters such as texture and flavor of Cantonese bakery after the change of food composition.This study has important practical significance for the healthy development of the whole bakery industry and high-quality bakery.COFs selected as a solid adsorbent to enrich ultra-trace HAs in Cantonese bakery requires a strong interaction between COFs and HAs.Based on the extra-ring amino groups in heterocyclic amine molecules,TpBD-COF was selected as the basic material,Carboxyl modification of TpBD-COF was carried out by bottom-up method and post-modification method,and two new materials with different structures of CTpBD-COF and TpBD-COOH-COF were obtained.The characterization of the crystallinity,functional groups,surface properties of three kinds of COFs materials and their adsorption kinetics and isothermal adsorption behavior on 16 kinds of HAs were systematically explored.Combined with the change of material structure,the relationship between adsorption performance and structure was revealed,and finally the adsorbent material with excellent performance was obtained.The results show that the ketene amine structure of the three materials is formed and the corresponding organic frame materials were obtained.After the introduction of carboxyl group,the degree of crystallization decreased obviously,and the crystallization directly affected the formation of pores in the material.At the same time,the specific surface areas of TpBD-COOH and CTpBD decreased from 161 m²·g^-1 to 96 m²·g^-1 and 18 m²·g^-1 respectively.After carboxyl modification,the hydrophilicity of the material was enhanced.TpBD-COOH-COF obtained by post-modification method has stronger adsorption capacity,and the maximum adsorption capacity obtained by isothermal adsorption model is 297.62～4438.35μg·g^-1,indicating that the adsorption of materials to HAs is the result of the interaction of pore structure and carboxyl groups.Using the obtained TpBD-COOH as adsorbent material,a membrane protective micro-solid phase extraction device was prepared with polypropylene microporous membrane,and the adsorption and desorption conditions in the extraction process were optimized.Finally,combined with HPLC-MS,a method for rapid and accurate enrichment of HAs in Cantonese bakery was established.The detection limit of this method for 16 kinds of HAs in Cantonese bakery is 0.037～1.387μg·kg^-1,and the minimum quantitative limit is 0.093～3.413μg·kg^-1.The recovery rate in Cantonese bakery with scalar quantity of 5,20 and 100μg·kg^-1 is 81.9～112.0%,76.6～118.7%,72.6～118.5%,respectively.The intra-day and inter-day relative standard deviations of Cantonese bakery with scalar quantities of 5,20 and 100μg·kg^-1 are less than 10%,showing good stability.Compared with the detection methods reported in the literature,this method can detect more types of HAs,with higher sensitivity and accuracy,and a wider range of application,so it is a more applicable detection method.Based on the established HAs enrichment detection method,the inhibitory effects of the types and substitutions of sugar alcohols on HAs and acrylamide（AA）in Cantonese bakery were explored.At the same time,the effects of the type and amount of sugar alcohols on the quality indexes such as food texture and taste were also investigated.The results showed that erythritol had the best inhibitory effect on the total production of HAs and AA in moon cake,chicken cake and almond cake.After 50%of sucrose in the three bakery was replaced by erythritol,the total production of the two types of hazards in moon cakes,chicken cakes and almond cakes decreased by 72.1%,57.0%and 68.6%,respectively.Erythritol has little effect on the texture properties of the three kinds of food.With the continuous improvement of the replacement amount of erythritol,the inhibitory effect on the total amount of harmful substances in the three Cantonese bakery was more significant,but had no significant effect on their texture properties.After sucrose was replaced by sugar alcohol,the taste quality of the original food changed to a certain extent,but the effect on the taste quality could be reduced by controlling the substitution amount of sugar alcohol in three kinds of Cantonese bakery.In this paper,through the carboxylation modification of TpBD-COF,the TpBD-COOH-COF material with excellent adsorption properties for HAs was obtained and used as an adsorbent to prepare a membrane-protected micro-solid phase extraction device.Combined with HPLC-MS,a rapid and accurate method for the determination of HAs in Cantonese bakery was established.Based on this method,it was found that erythritol had a significant inhibitory effect on the total production of HAs and AA in moon cake,chicken cake and almond cake.By adjusting the amount of substitution,its inhibitory effect on harmful substances can be controlled,and at the same time,Cantonese bakery can maintain good texture properties and taste quality.The research results provide a theoretical basis for the creation of high-quality and healthy Cantonese bakery.更多还原