英文版食品添加剂概述 (6).pdf

Common food additives:Part two Food safety Outline 01 02 03 Bleaching agent Colorant Color fixative Bleaching agent Definition:Bleaching agent is a group of food additives which are used to destroy or inhibit the factors of color development of food to discolor food or prevent food from browning，so as to enhance the color and lustre of food.Classification:Reduction type(sulfur dioxide,sulfite and sulfur,etc.)and oxidation type(benzoyl peroxide and hydrogen peroxide,etc.).At present,the most used is the reduction type and the oxidation type is no longer used in food.Mechanism of reduction bleaching agent Take sulfur dioxide as an example:First,when sulfur dioxide meets water,it forms sulfurous acid with strong reducibility,which can reduce coloring substances in food and make them fade;Second,in plant-derived foods,sulfurous acid can also inhibit oxidases related to browning,thereby prevent browning;Third,sulfurous acid can also undergo the addition reaction with sugar in food to prevent non-enzymatic browning caused by the sugar-ammonia reaction.In addition,sulfurous acid can block the physiological oxidation process of microorganisms and then have an inhibitory effect on bacteria,fungi and yeast.Therefore,sulfur dioxide is both a bleaching agent and a preservative.Other common bleaching agents Sulfite:Includes sodium sulfite,sodium hydrogen sulfite and sodium hydrosulphite,etc.Need to form sulfurous acid under acidic conditions to play a bleaching effect.Mainly used in preserved fruit,dried fruits,etc and not suitable for animal foods(e.g.fish and meat)because the residual odor can mask the smell of rotten fish and meat and destroy vitamin B1.Sulfur:Sulfur needs to be combusted to generate sulfur dioxide and play a bleaching effect by fumigation.Bleach hygiene management Regulations in China:The reduced bleaching agents are mainly used in dried fruits,preserved fruit,dried vegetables,fruit and vegetable juices,wine,fruit wine,beverages and other foods.The maximum usage amount is 0.01-0.9g/kg in terms of sulfur dioxide.Colorant Definition:Colorant is a group of food additives that color food to improve the sensory properties,also known as pigment.Colorants can be divided into natural and synthetic colorants.Natural colouring Natural colorant:Mainly derived from metabolites of animals,plants and microorganisms and obtained by certain processing methods.Classification:plant pigments(lycopene,capsicum,curcumin,etc.),animal pigments(lac dyer red,cochineal,etc.)and microbial pigments(monascus red,etc.).At present,more than 100 natural colorants have been developed globally and about 40 natural colorants are allowed in China.Common natural colorants Monascus red(microbial colorant):Derived from the metabolites of monascus purpureus inoculated on rice.Fat-soluble and resistant to acids and alkalis,but fade after exposure to sunlight.A strong coloring power for protein-rich foods.Regulations in China:Except for flavoured and fermented milk and cakes and pastries,it can be used in other foods according to production needs.Lac dyer red(animal colorant):A colored metabolites secreted by laccifer lacca.One of its characteristics is that the color tone can change with PH.For example,when the pH is 3-5(acidic),it is red;when it pH is 6,it is red to purple;when the pH is greater than 7(alkaline),it is purple.Regulations in China:The maximum usage amount is 0.5g/kg.Common natural colorants Lycopene:A kind of carotenoid,which can provide bright red and come from a wide range of sources.The content is relatively rich in tomato,pumpkin,mango,persimmon,peach,grape and other fruits and carrot root and other plant roots.Also a polyunsaturated aliphatic hydrocarbon and has a strong antioxidant effect.Therefore,it is also widely used as a new type of natural antioxidant.Regulations in China:Can be used in dairy products,candy,seasonings,jellies,and other foods.The maximum usage amount is 0.015-0.06g/kg.Synthetic colorants Synthetic colorants:Prepared from tar oil or synthesized from aromatic hydrocarbon compounds,such as benzene,toluene and naphthalene,also known as tar oil colorants or aniline colorants.Generally,not as safe as natural colorants,but they have stable properties and strong coloring power,can be changed to the different color tone at will,and have low cost.Synthetic colorants Classification by the chemical structure:Azo colorant(amaranth,lemon yellow,etc.)and non-azo colorant(erythrosine,bright blue,etc.).The main synthetic colorants currently used in the world are water-soluble pigments.Regulations in China:The synthetic colorants can be used in frozen beverages,dairy products,preserved fruit,jams,compound wine,jelly,puffed food,chocolate,and other foods.The maximum usage amount is 0.025-0.5g/kg.Color fixative Definition:Colour fixative is a non-colorant substance that can interact with the certain substances in meat and meat products to generate the stable colored substances enduring the processing and storage,also known as color former,About seven color fixative are allowed in China,including nitrate,nitrite,ferrous gluconate,and ascorbic acid.The color fixatives used frequently are nitrate and nitrite,which mainly used for meat curing.Mechanism of color fixation First,when meat is cured,after adding nitrite and nitrate,nitrite is converted into nitrous acid under the acidic conditions caused by lactic acid and nitrate needs to be converted into nitrite under by the nitrate-reducing bacteria and then converted to nitrous acid;Second,nitrous acid is unstable and decomposes to release NO(nitrogen oxide).NO replaces iron in myoglobin to form bright red nitroso myoglobin.NO can also directly reduce ferric myoglobin to form nitroso myoglobin;Third,nitroso myoglobin is unstable and needs to be heated,fumigated,and salted to denature protein and then transformed into a stable ferrous nitric oxide hemochromogen showing a pink color.In addition,nitrate has a certain inhibitory effect on microorganisms,especially for Clostridia,and then has a preservative function.Nitrite can also form a unique flavor of cured meat.Health hazards of nitrate and nitrite First:If the body ingests a large amount of nitrite by mistake,the hemoglobin can be oxidized into methemoglobin and then deprived of the ability to transport oxygen,which results in hypoxia and even cyanosis.Second:Nitrate and nitrite are also the precursors of N-nitroso compounds.Under suitable conditions,the carcinogenic N-nitroso compounds can be produced.Methods and regulations to reduce health hazards Methods:First:Minimize the use of nitrate and nitrite if expected effect is reached Second:Use the substitutes of nitrate and nitrite when the manufacturing technique is allowed to use them.Third:Use color development aids(e.g.ascorbic acid and niacinamide)to reduce the usage amount of nitrate and nitrite.Regulations in China:the maximum usage amount of nitrate in meat products is 0.50g/kg the maximum usage amount of nitrite in canned meat,meat products,and western-style ham is 0.15g/kg.Summary Thank you for your participation！