面包品质改良剂的研究进展

作为食品添加剂,面包改良剂在面包制作中起到重要的作用。面包改良剂能延缓面包的老化、改善面包的筋力及机械加工性能、提高面包的品质,使其在色、香、味、形上更好地满足消费者的需要。本文主要阐述面包品质改良剂：氧化剂、乳化剂、酶制剂、胶体物质,和它们的作用机理,还介绍了溴酸钾替代品及复配型面包改良剂的研究进展。     

Food emulsifiers—Science and art

General classifications of food emulsifiers are presented, and their functions are discussed. Examples of many food products are given, and recommended emulsifier usage levels are presented. Some of the food applications cited include: cakes, icings, toppings, bread, sweet goods, frozen desserts, coffee whiteners, peanut butter, margarine and confectionery coatings. One of seven papers presented in the Symposium “Fats and Oils in the Food Industry,” Atlantic City, October 1971.     

Soap and fat-based detergents

Many materials made from fats and oils derive their importance from their ability to modify the surface behavior of the liquid in which they are dissolved. These compounds are grouped under the broad classification of surface active agents or surfactants. Depending on their use, they are classified as detergents, wetting agents, emulsifiers, dispersing agents, etc. The oldest, and still one of the most important surfactants, is ordinary soap; twentythree percent of all the tallow produced in the United States goes into soap. This paper covers the present state of the art of soap technology, and the most important classes of fat-based surfactants.     

Emulsifiers Used in Margarine,Low Calorie Spread,Shortening, Bakery Compound and Filling

Emulsifiers used in the Food Industry improve texture, stability, volume, softness, aeration, homogenization and shelf life. By reducing interfacial tension between oil and water they facilitate the formation of emulsions. Emulsifiers used to give fine disperse and stable w/o emulsions in margarine, factors influencing spattering in frying margarine and which emulsifiers that give optimal effect are discussed. Stabilization of low calorie spread emulsions and use of the right emulsifier is very important for achieving a stable spread. The influence of emulsifiers on quality in cake and puff pastry margarine and the prevention of sandiness in margarine are illustrated. Shortening is a complex product group, and the use of emulsifiers depends on the application of the shortening, this is discussed. In bakery compound used for yeasted white bread and filling containing sugar syrup emulsifiers give improved stability.     

Glycidol and 3-MCPD Analysis Methods for Mono- and Diglycerides

Distilled monoglycerides (DMG) and mono-di-glycerides (MDG) are commonly used as emulsifiers in various processed foods, e.g., bread, margarine, and ice cream. DMG and MDG are derived from triacylglyceride (TAG) oils, and thus it is speculated that the harmful substances glycidol and 3-monochloropropane-1,2-diol (MCPD) or their esters can also appear in DMG and MDG as they do in edible oil. However, present analysis methods, often developed for MCPD esters and glycidyl esters in TAG oils are not suitable for many DMG and MDG products. Dissolution of the DMG and MDG is the main problem. In this work a method for quantifying content of glycidol esters (GE) and 3-MCPD using an indirect method quantifying the compounds with GC-MS has been tested. The development has been developed based on the American Oil Chemists' Society (AOCS) Cd 29c method including the modifications implemented by Axel Semrau in the automated procedure for triglycerides. With the proposed procedure it is shown that the new analysis method produces valid results in the range 1–10 ppm, and acceptable results at 0.5 ppm for both 3-MCPD and glycidol. The method is an important part of providing safe and healthy emulsifier improved food products to consumers in European Commission and the rest of the world. Practical Applications: The European Commission (EU) has requested the emulsifier industry to supply data for GE and MCPD content as a first step in making legislation for maximum content as in edible oils and fats. However, there is no analysis method for emulsifiers (e.g., mono- and diglycerides). This work is a contribution to development of such an analysis method.     

Use of oil in baked products—Part I: Background and bread

The benefits of fat systems in yeast-raised and chemically leavened baked goods are reviewed. The effects of rising ingredient costs and competition on ingredient technology are described, leading to a discussion concerning the trend in the United States to switch from the standard shortenings—lard and partially hydrogenated vegetable shortening—to oil in baked products. Problems associated with the incorporation of oil in bread formulations follow. Test work has shown that surfactants are effective additives in overcoming these negative and in promoting the production of quality products. A comparison of oil versus lard as the shortening medium in bread is described. Evaluation of emulsifiers with oil in bread are discussed. Presented at the American Oil Chemists’ Society, San Francisco, CA, April 29-May 3, 1979.     

Functions of emulsifiers in food systems

The function of food grade emulsifiers in various food products (emulsions, starch based food, yeast raised bakery products, etc.) are reviewed. The stability of emulsions against coalescence of dispersed droplets is among other factors dependent on monoor multimolecular interfacial films with viscoelastic properties formed by adsorbed emulsifier molecules. Agglomeration of fat globules in whippable emulsion is needed to obtain desired foam stability and texture and can be controlled by lipophilic emulsifiers. Complex formation with starch components (amylose) is influenced both by the chemical structure of an emulsifier and by its physical behaviour in water. Interaction with proteins takes place primarily with anionic emulsifiers or very hydrophilic, nonionic types, which thereby improves the rheological properties of wheat gluten. Emulsifiers are also used as crystal modifying agents in fats where polymorphic changes during storage creates texture problems.     

Utilization of mathematical models to characterize functional properties of selected emulsifiers in continuous mix bread

Research conducted to determine the functional properties of food emulsifiers encompassed by the Bread Standards facilitated the development of mathematical models. Areas of functional utility are characterized by this mechanism. Emulsifiers were investigated individually and in combination with a complementary softener or conditioning agent. The evaluation resulted in classified functionality and ranked responses for specified areas of: (a) bread softness retention, (b) shock tolerance, and (c) specific bread volume. Mathematical techniques employed to describe the models consist of equations having the form: {ie397-01} Binary mixture experiments utilizing interaction modeling to describe functional properties were employed. Regression equations were developed to define staling-softness effects for the investigated emulsifiers. Synergistic responses are also identified. Potential commercial applications via computerization are discussed to assist in selecting emulsifier systems for specific functional applications.     

Sugar-based surfactants for consumer products and technical applications

Sugar-based surfactants, such as sorbitan esters, sucrose esters, alkyl polyglycosides, and fatty acid glucamides gain increasing attention due to advantages with regard to performance, health of consumers, and environmental compatibility compared to some standard products. Sorbitan esters are well established products, which are mainly used as leather and textile auxiliaries or as emulsifiers for food at a volume of approx. 20,000 t/a. Sucrose esters are relatively hydrophobic products. The actual market size is estimated to be < 4,000 t/a – the main application being emulsifiers for food and cosmetics. Their use is still limited. Alkyl polyglycosides and fatty acid glucamides represent a perfect amphiphilic structure with excellent surface activity as well as solubility due to highly selective syntheses. For alkyl polyglycosides industrial processes have been developed in the past couple of years and a total capacity of ca. 80,000 t/a has been established. They are mainly used for cosmetic, manual dishwashing, and detergent applications. Fatty acid glucamides to date are exclusively used by one company in liquid and powdered detergents. The estimated production capacity is approx. 40,000 t/a. Comparable in their performance profile as co-surfactants, both products differ in their raw material base: whereas in the case of the fatty acid glucamides methylamine is incorporated in the product, alkyl polyglycosides are completely based on renewable resources. This, combined with very good performance and mildness, could be one reason why alkyl polyglycosides are the most successful sugar-based surfactants nowadays. Research to develop derivatives on this basis is still ongoing.     

食品乳化剂的安全性及JECFA评价结果

FAO/WHO食品添加剂和污染物联合专家委员会(简称JECFA)是国际食品添加剂与污染物安全评价的权威机构,对世界各国所用食品添加剂的安全性进行评价。食品乳化剂是食品工业中一类重要的使用广泛的添加剂。介绍了JECFA关于食品乳化剂的主要品种及使用情况,总结了JECFA对食品乳化剂的安全性评价意见及规定标准。     

Recent trends in usage of fats and oils as functional ingredients in the baking industry

Throughout the history of the human race, cereal grains have been a source of staple food throughout this Earth. Except for the rice-eating countries, bread is the principal food and provides more nutrients than any other single food source. In over half of the countries around the world, bread supplies more than 50% of the total caloric intake. Even in one of the wealthiest nations, the United States, cereal grain products supply over 25% of the food energy, ca. 20% of the proteins, 14-18% of fats, and over 40% of carbohydrates.     

Metabolomics as a Tool to Elucidate the Sensory,Nutritional and Safety Quality of Wheat Bread—A Review

Wheat (Triticum aestivum) is one of the most extensively cultivated and used staple crops in human nutrition, while wheat bread is annually consumed in more than nine billion kilograms over the world. Consumers’ purchase decisions on wheat bread are largely influenced by its nutritional and sensorial characteristics. In the last decades, metabolomics is considered an effective tool for elucidating the information on metabolites; however, the deep investigations on metabolites still remain a difficult and longtime action. This review gives emphasis on the achievements in wheat bread metabolomics by highlighting targeted and untargeted analyses used in this field. The metabolomics approaches are discussed in terms of quality, processing and safety of wheat and bread, while the molecular mechanisms involved in the sensorial and nutritional characteristics of wheat bread are pointed out. These aspects are of crucial importance in the context of new consumers’ demands on healthy bakery products rich in bioactive compounds but, equally, with good sensorial acceptance. Moreover, metabolomics is a potential tool for assessing the changes in nutrient composition from breeding to processing, while monitoring and understanding the transformations of metabolites with bioactive properties, as well as the formation of compounds like toxins during wheat storage.     

Evaluation of the use of surfactants as additives in enzymatic glycerolysis reactions

MAGs and DAGs are widely used as emulsifiers in many industries. During glycerolysis reactions for their production, the immiscibility of the glycerol and the oil phases is an important drawback for practical purposes. For overcoming this problem, the use of a food grade surfactant can be an important alternative to improve system homogeneity, leading to high TAGs conversion in short reaction times. On the other hand, food grade surfactants have bonds that could be modified by lipases. The main interest of this work was to qualitatively verify the reactivity of different Tween and soy lecithin used as additives in glycerolysis reactions in the presence of Candida antarctica B lipase. The biocatalyst had activity toward all tested surfactants in the experimental conditions chosen for the tested reactions. Despite this, MAG and DAG could be produced when using Tween 85 as additive in the enzymatic glycerolysis of fish oil. Our results therefore suggest that tested Tween and soy lecithin can be used as surfactants in glycerolysis reactions, but one has to consider their reactivity in the presence of lipases. Practical applications : This work investigates the reactivity of synthetic (Tween) and natural (soy lecithin) surfactants in the presence of lipase during glycerolysis reactions. Tween 85 was further applied in different reaction media for a better understanding of the modifications it was undergoing. The biocatalyst had activity toward almost all tested surfactants in the experimental conditions chosen for the preliminary assays herein performed, as qualitatively verified by thin‐layer chromatography. This result suggests that the use of phosphatides and polyoxyethylene esters as additives in glycerolysis systems has to be well evaluated as their enzymatic modification may generate problems during downstream processes for the recovery of the desirable products. The present report is part of a broader project aiming at building a platform to allow developing new processes for the production of emulsifiers through enzyme‐catalyzed glycerolysis reaction.     

Emulgatoren aus Schlachttierfetten

Emulsifiers from Animal Fats The terms ?Emulsion”? and ?Emulsifier”? are defined and modified. Natural and synthetic emulsifiers used currently in foods are reviewed and mono-/diglyceride emulsifiers prepared from fats, which constitute a major portion of the products marketed, are discussed in details. Preparation, properties and applications of these emulsifiers in margarine, shortenings, ice creams and other foods are given. It is emphasized that animal fats, after refining and hardening, are highly suitable as starting material for the preparation of mono-/diglyceride emulsifiers having unobjectionable taste and good stability. These products are in no way inferior to those obtained from vegetable oils and fats.     

Stepwise optimisation of enzyme production in solid state fermentation of waste bread pieces

When it is not consumed, bread presents a major source of food waste, both in terms of the amount and its economic value. However, bread also possesses the characteristics of an ideal substrate for solid state fermentation. Yet nearly all wasted bread ends up in landfill sites, where it is converted into methane by anaerobic digestion. Governments are finally taking action and, according to the EU Landfill Directive, for example, biodegradable municipal waste disposed into landfills must be decreased to 35% of 1995 levels, by 2020. Solid state fermentation of waste bread for the production of value added products is a novel idea, which could help with the achievement of this target. In this study, glucoamylase and protease production from waste bread pieces, via solid state fermentation, was investigated in detail. The optimum fermentation conditions for enzyme production were evaluated as, 20 mm particle size, 1.8 (w/w, db) initial moisture ratio, and duration of 144 h. Under these conditions, glucoamylase and protease activities reached up to 114.0 and 83.2 U/g bread (db), respectively. This study confirms that waste bread could be successfully utilised as a primary raw material in cereal based biorefineries.     

Food uses of sunflower proteins

Commerical use of sunflower meal as a food product is dependent on the development of low chlorogenic acid cultivars and efficient procedures for dehulling the high oil cultivars and hybrids. Laboratory defatted sunflower flours have high protein contents, bland flavors, white colors at acid pH levels, and contain no antinutritive factors. Functional test data show that sunflower flours and protein concentrates have high salt solubility, oil absorption and oil emulsification. In rat feeding trials, the low lysine level in sunflower proteins has resulted in low protein efficiency ratios for sunflower diets and blends with cereals including bakery products. High weight gains are obtained for sunflower blends with legume and animal proteins, suggesting applications in milk and meat extenders and in soybean-based infant, formulas. Heat treatments, mechanical agitation, and emulsifiers were effective in solubilizing 80% of sunflower proteins in extended milk formulations, and the product was given high ratings in taste panel evaluations. Sunflower flour slurries show excellent whippability and foam stability, comparable to that of soybean protein isolate, but lack the ability to form a firm gel. Wieners supplemented with sunflower products have low shrinkage and cooking losses, but rate poorly in organoleptic tests. Texturization of sunflower flour by extrusion cooking gave fibrous chunks which were greyish in appearance, but had a chewy texture, a meat-like flavor, and gave low cooking losses in beef pattie formulations. Spun sunflower protein/casein (1:1) blends are superior to other vegetable proteins in shear strength, swellability and firmness. Sunflower flours are particularly deleterious to bread loaf characteristics. This effect can be partially overcome by autoclaving the flour, concentration of the protein, or addition of gluten, but the protein nutritive value of the supplemented bread is only marginally improved.     

Supplementation of bakery items with high protein peanut flour

White skin peanuts were defatted with hexane to produce flours with 55–60% protein. The peanut flour was used to replace 12.5% of the wheat flour in bread, 100% of wheat flour in muffins, and 10, 15 or 50% of the wheat flour in cookies. At 12.5% levels of peanut flour, total solids, protein, moisture retention of bread after baking, and dietary fiber contents are increased without affecting loaf vol-ume. Crust color of supplemented bakery items is darker brown, texture is coarse for bread and harder in cookies, but not enough to make them unacceptable. Peanut flour muffins with a net protein content of 33–40% can serve as a high protein snack food or bakery item, possibly for patients with celiac disease who cannot tolerate wheat flour. Moisture retention in supplemented products was greater than in nonsupplemented controls. Net increase of protein in baked items varied from 4% increase for 12.5% peanut flour bread to 30% for the all-peanut flour muffins. Other physical and chemical prop-erties of these products are presented to support potential applica-tions of peanut flour as a supplement for selected food products.     

Analysis of nonvolatile lipid oxidation products in vegetable oils by normal-phase high-performance liquid chromatography with mass spectrometric detection

Nonvolatile triacylglyceride (TAG) oxidation products play an important role in the oxidative degradation of lipids. They serve as a reservoir of oxygen-containing species and hence can act as off-flavor precursors or as initiators for further oxidation reactions. Possible nonvolatile lipid oxidation products are TAG with a hydroperoxy, hydroxy, epoxy, or oxo (ketone or aldehyde) group or combination of these groups. The breakdown of TAG hydroperoxides yields nonvolatile glyceride species with two intact fatty acid chains and one short chain mostly ending in an aldehyde or hydroxy group (2 1/2 glycerides). By means of normal-phase high-performance liquid chromatography (HPLC) with mass spectrometric (MS) detection, non-volatile lipid oxidation products can be separated according to polarity. This results in separation into classes of TAG oxidation products, such as epoxy-TAG, oxo-TAG, hydroperoxy-TAG, hydroxy-TAG and 2 1/2 glycerides, which can be identified using selected ion chromatograms. The retention times of TAG oxidation products on the normal-phase HPLC system and the signal intensity of the MS detector are stable enough to enable quantitative analysis based on external calibration. The normal-phase HPLC-MS method is very suitable for the characterization and quantitation of nonvolatile TAG oxidation products in oxidized TAG reference compounds as well as in real oils or oil phases isolated from emulsions, spreads, or other fat-based food products. This method can give detailed information for the study of lipid oxidation mechanisms. Presented at the 15th Montreux Symposium on Liquid Chromatography/Mass Spectrometry, Montreux, Switzerland, November 9–10, 1998.     

Composition and potential contribution of iron, calcium and zinc of bread and pasta made with wheat and amaranth flours

Amaranth, a traditional american crop that is nowadays given renewed importance, has good food potential value. The minerals contributed by the grain are quantitatively important. However, as the flour is obtained by total grinding of the grain, this process leads to the presence of anti-nutritional components, such as fitates, and therefore, the evaluation of the actual availability of the minerals of nutritional interest becomes necessary. The process of bread fermentation, plus the addition of fitases and enhancers of mineral availability such as citric and ascorbic acid, might improve mineral bioavailability. The objective of this work was to assess protein, ash, lipids and total dietary fiber content and evaluate the concentration and dialyzability of Fe, Zn and Ca (as mineral bioavailability indicator) in bread and pasta 100% wheat, and bread and pasta obtained by replacing 20% wheat flour (WF) with whole amaranth flour (WAF). Ascorbic acid (AA), citric acid (CA) and fitase were used as mineral bioavailability enhancers. The potential contribution of each mineral (PC) was calculated as each mineral concentration times its dialyzability. In 80:20 bread an increase of total dietary fiber and minerals, compared to 100% wheat products was observed. A maximum FePC in 80:20 bread was obtained with CA and fitase (0.55mg%). In pasta, the maximum effect was observed with CA (0.07 mg%). The CaPC was maximum in 80:20 pasta with CA (16.72 mg%). The greatest ZnPC was found in 80:20 bread with CA and fitase (0.40 mg%). The introduction of the WAF in fermented baked products with addition of CA and fitase allows to obtain nutritional advantages.     

Die Wirkung von emulgierenden Lipiden auf die Backeigenschaften des Mehles

Effect of Emulsifying Lipids on Banking Quality of Wheat Flour Fatty acids, monoglycerides and monoglycerin ethers were tested for their suitability as emulsifiers in bread making. The addition of myristic or palmitic acid did not affect the bread volume. Stearin acid increases the volume of bread, while the addition of oleic acid impairs the volume and the score number of the bread. Monoglycerides improve the quality of the bread. Glycerinmonomyristate has the highest effect, followed by the unsaturated monoglycerides. In these experiments, the glycerinmonooleate and glycerinmonolinoleate had higher effect on the bread volume than glycerinmonopalmitate. It has been found of interest to investigate the effect of adding monoglycerin ethers in relation to baking properties of flour. The addition of rac-l-O-dodecylglycerin and rac-l-O-tetradecylglycerin improved the bread volume for about 15% and 13%. The rac-l-O-octadecylglycerin has lower effect than the monoglycerin ethers with C₁₂ and C₁₄.