No full-text available
To read the full-text of this research,
you can request a copy directly from the authors.
Diacetyl Tartaric Esters of Monoglycerides (DATEM) and Associated Emulsifiers in Bread Making
Abstract
Diacetyl tartaric esters of monoglycerides (DATEM) are glycerol derivates esterified with edible fatty acids and mono- and diacetyl tartaric acids. All the different types of DATEM are esters of a polyvalent alcohol, so they show reactions of rearrangement, intra- and intermolecular migration of acylic groups and a certain sensitivity towards hydrolysis. Mono- and diacetyl tartaric acid esters of mono- and diglycerides are used as dough conditioners for all baked products, particularly yeast-leavened products, white bread, rolls, rusks, and in flour mixes for convenience food. This chapter focuses on the action of DATEM within the processing of baked goods based on wheat flour. The use of emulsifiers or combinations of different emulsifiers in fine baked goods offer many advantages during processing and storage. Some of the most important ones are: simplification of the dough and/or baking mass preparation, reduction of baking fat, and improvement in chewing and taste properties.
... DATEM include glycerol derivatives esterified with edible fatty acids and mono-and diacetyl tartaric acid [8], generally permitted for the use in foodstuffs and as dough conditioners for all baked products, particularly yeast-leavened products, such as white bread. Their HLB value is 8-10. ...
... DATEM comes as a sticky viscous liquid, or with a consistency like fats, or yellow waxes, or in flakes or powder form. DATEM is more hydrophilic compared to the mono-and diglycerides, and its starting materials [8]. ...
... Ionic emulsifiers, such as DATEM, offer a huge ability toward the formation of hydrogen bridges with amidic groups of the gluten proteins [8]. Diacetyl tartaric acid (DATA) esters bind rapidly to the hydrated gluten proteins and, as a result, the gluten network formed becomes stronger, more extensible and more resilient, producing a uniform and stable gas cell structure [5]. ...
... DATEM are esters of polyvalent alcohols that consist of glycerol derivates esterified with edible fatty acids and mono-and diacetyl tartaric acids. There could be an interand intra-exchange of acylic groups, resulting in small amounts of free glycerol, free fatty acids, and free tartaric and acetic acids [20]. DATEM's advantages are reducing baking fat, improving chewing and taste properties, and increasing resistance during processing [18,20]. ...
... There could be an interand intra-exchange of acylic groups, resulting in small amounts of free glycerol, free fatty acids, and free tartaric and acetic acids [20]. DATEM's advantages are reducing baking fat, improving chewing and taste properties, and increasing resistance during processing [18,20]. Some industries have also changed from DATEM to lipase enzymes, but more information and studies are still needed to evaluate its use in bread characteristics [19]. ...
Bread is considered a staple food worldwide, and therefore there is much interest in research around the topic. The bread industry is usually looking for ways to improve its formulations. Therefore, other ingredients such as dough conditioners, crumb softeners, emulsifiers, and surfactants can be added to enhance bread quality. These ingredients perform functions such as helping standardize processes in the industry, reducing dough-mixing time, increasing water absorption, improving bread quality, and extending its shelf life. Consumers are concerned about the effect of these ingredients on their health, and this has increased the popularity of clean-label bread formulations. A clean label generally indicates that a product is free of chemical additives, has an ingredient list that is easy to understand, has undergone natural or limited processing, and/or is organic and free of additives or preservatives. However, there is no scientific definition of the term “clean label.” Researchers have focused on these clean-label initiatives to replace dough strengtheners and preservatives in bread formulations and give consumers what they perceive as a healthier product.
... It was suggested that the antifirming properties of DATEM may be due to changes in cell wall thickness and elasticity of bread crumb. Gaupp and Adams (2004) explained that the most important effects induced by the addition of DATEM are the stabilization of a soft crumb, which causes a delay in starch retrogradation and improved dough performance during manufacturing. In gluten-free bread formulations, the impact of DATEM addition has been shown to have both positive and negative effects depending on the formulation used (Nunes and others 2009;Demirkesen and others 2010). ...
... Volume differences due to DATEM were 0.73 cm 3 /g and 0.17 cm 3 /g for the 0% and 25% egg level, respectively. DATEM has been shown to increase loaf volume in breads containing gluten (Gaupp and Adams 2004). Volume increases have been attributed to DATEM's ability to form liquid films of lamellar structure in the interphase between the gluten strands and the starch in wheat dough systems (Stampfli and Nersten 1995). ...
... The most-used improvers in the bakery are amylolytic enzymes such as α-amylase from cereal malt [6,7]), fungal α-amylase from Bacillus subtilis [8] or Lactobacillus plantarum [9], β-amylase [10], and fungal amyloglucosidase from Aspergillus niger [11]; as well as proteolytic enzymes such as malt proteases [12], proteases from A. oryzae [13] and vegetable proteases (papain, bromelain); pentosanases such as exogenous or fungal xylanases [14][15][16]; fungal lipases [17]; lipoxygenases from wheat or soy flour [12]; transglutaminase produced by the bacterium Streptoverticillium [12]; cellulases [10]; natural emulsifiers such as lecithin from oil demucilagination [18,19]; synthetic emulsifiers such as polyalcohol esterified with paraffin chains [20]; oxidizing agents such as L-ascorbic acid (E300) [21], KBr (E924) [22,23], KI (E917) [24]; and reducing agents such as L-cysteine [25]. ...
An in-depth analysis of wheat flour (WF) substituted with 0.5–2.5% rosehip powder (Rp) concerning the proximate composition, dough farinographic properties, and bread physico-chemical characteristics was performed. The purpose of this study was to investigate whether the use of Rp as a natural alternative for synthetic ascorbic acid in breadmaking was appropriate. A sample of wheat flour with an ascorbic acid addition of 2 mg/100 g was also used. Rp showed higher ash, carbohydrates, and fibre content, as well as lower moisture and protein content compared to wheat flour, and a vitamin C content of 420 ± 16.09 mg/100 g. A proximate composition analysis revealed a decrease in moisture, protein, and wet gluten, and an increase in ash, carbohydrates, and fibres for the flour mixtures compared with WF. Farinographic properties were positively influenced by the Rp addition and the high fibre content in the flour mixtures. Water absorption increased from 58.20% (WF) to 61.90% (2.5% Rp). Dough stability increased for the 0.5–1.0% Rp addition, then slightly decreased. The physico-chemical properties of bread prepared from flour mixtures showed a significant increase in height: 100.10 ± 0.14 mm (WF)–115.50 ± 0.14 mm (1.5% Rp), specific volume: 142.82 cm3/100 g (WF)–174.46 cm3/100 g (1.5% Rp), moisture: 41.81 ± 0.40% (WF)–43.92 ± 0.15% (2.0% Rp), and porosity: 87.75 ± 1.06% (WF)–89.40 ± 0.57% (2.5% Rp). The results indicated that the Rp used in breadmaking to replace synthetic ascorbic acid could be suitable.
... Mixed acetic and tartaric acid esters of mono-and diglycerides of fatty acids (E 472f) are obtained either by reaction of mono-and diglycerides of fatty acids with tartaric acid anhydride in the presence of acetic acid, or by esterification of mono-and diglycerides with tartaric acid and acetic acid in the presence of acetic acid anhydride (Gaupp and Adams, 2004). ...
... Mixed acetic and tartaric acid esters of mono-and diglycerides of fatty acids (E 472f) are obtained either by reaction of mono-and diglycerides of fatty acids with tartaric acid anhydride in the presence of acetic acid, or by esterification of mono-and diglycerides with tartaric acid and acetic acid in the presence of acetic acid anhydride (Gaupp and Adams, 2004). ...
Abstract The Panel on Food Additives and Flavourings (FAF) provided a scientific opinion re‐evaluating the safety of acetic acid, lactic acid, citric acid, tartaric acid, mono‐ and diacetyltartaric acids, mixed acetic and tartaric acid esters of mono‐ and diglycerides of fatty acids (E 472a‐f) as food additives. All substances had been previously evaluated by the Scientific Committee for Food (SCF) and by the Joint FAO/WHO Expert Committee on Food Additives (JECFA). Hydrolysis of E472a,b,c,e was demonstrated in various experimental systems, although the available data on absorption, distribution, metabolism, excretion (ADME) were limited. The Panel assumed that E472a‐f are extensively hydrolysed in the GI tract and/or (pre‐)systemically after absorption into their individual hydrolysis products which are all normal dietary constituents and are metabolised or excreted intact. No adverse effects relevant for humans have been identified from the toxicological database available for E472a‐f. The Panel considered that there is no need for a numerical acceptable daily intake (ADI) for E 472a,b,c. The Panel also considered that only l(+)‐tartaric acid has to be used in the manufacturing process of E472d,e,f. The Panel established ADIs for E 472d,e,f based on the group ADI of 240 mg/kg body weight (bw) per day, expressed as tartaric acid, for l(+)‐tartaric acid‐tartrates (E334‐337, 354) and considering the total amount of l(+)‐tartaric acid in each food additive. Exposure estimates were calculated for all food additives individually, except for E 472e and f, using maximum level, refined exposure and food supplements consumers only scenarios. Considering the exposure estimates, there is no safety concern at their reported uses and use levels. In addition, exposure to tartaric acid released from the use of E 472d,e,f was calculated. The Panel also proposed a number of recommendations.
... crumb grain and uniformity of cells in the crumb Gaupp and Adams 2007). These effects must be prominent during the fermentation and baking process, so in our samples that have not fermented, the effect of DATEM was not revealed. ...
... Although DATEM is also a polar molecule (diacetil tartaric acid residue) it works cooperatively with gluten proteins and flour lipids at the air/water interface, improving gas-holding ability of dough. These interactions may be established mainly through hydrophobic bonds mediated by the hydrophobic part of the molecule [30]. Spectroscopic results suggest that for SSL-gluten systems interactions involve mainly amino acids with OH or charged residues (Table 3). ...
Changes in the secondary structure of gluten proteins due to emulsifiers were analyzed by Raman Spectroscopy. The protein folding induced by 0.25% SSL (Sodium Stearoyl Lactylate) (GS0.25, Gluten + 0.25% SSL) included an increase in α-helix conformation and a decrease in β-sheet, turns and random coil. The same behavior, although in a less degree, was observed for 0.5% gluten–DATEM (Diacetyl Tartaric Acid Esters of Monoglycerides) system. The low burial of Tryptophan residues to a more hydrophobic environment and the low percentage area of the C–H stretching band for GS0.25 (Gluten + 0.25% SSL), could be related to the increased in α-helix conformation. This behavior was also confirmed by changes in stretching vibrational modes of disulfide bridges (S–S) and the low exposure of Tyrosine residues. High levels of SSL (0.5% and 1.0%) and DATEM (1.0%) led to more disordered protein structures, with different gluten networks. SSL (1.0%) formed a more disordered and opened gluten matrix than DATEM, the last one being laminar and homogeneous.
The emulsifying properties of rice protein ingredients, and their behaviour in the presence of other non-protein emulsifiers, is essential to support food applications. The objective of this study was to investigate the influence of different low molecular weight surfactants (LMWS) on the stability of model infant formula emulsions (10 g protein L⁻¹, 35 g soybean oil L⁻¹, 50 g carbohydrate L⁻¹) based on a rice protein hydrolyzate (RPH). Inclusion of CITREM and DATEM, at concentrations greater than 1 g L⁻¹, gave emulsions with mean fat globule diameters (D[4,3]) less than 1 μm with good creaming stability, while lecithin was less effective across the concentration range tested (i.e., 1–3 g L⁻¹). Coalescence of the control emulsion was observed upon both storage (10 d at 4 °C) and heat treatment (95 °C × 5 min). Increasing CITREM concentration increased storage and heat stability of the emulsions, while addition of CITREM at 2 g L⁻¹ facilitated the formation of a very stable product. This study provides a first insight into the potential of hydrolyzed rice protein to be used as a value-added ingredient in the production of nutritional beverages such as infant formula emulsions, and the influence of LMWS on the stability of such products.
Lipids in one form or another make key contributions to bread quality with their main impact being related to the ability of the dough to retain gas. Lipids in bread dough formulae may come from indigenous sources (mainly the flour) or endogenous through recipe additions. There are a complexity of lipid factions in wheat flour which can be broadly split into polar and nonpolar forms: their contributions to bread quality are equivocal. The chemistry and physical form of the recipe fats are important if they are to contribute positively to bread volume. While not lipids, additions of emulsifiers to recipes deliver a range of improvements to bread quality similar to those of recipe fats, with additional benefits related to improving crumb softness and limiting bread staling.
Baking is a universal process for the preparation of baked products like, bread, biscuits, pastries, cookies, crackers, pies, and others. Although usage of enzymes in bakery is quite old but recent developments in basic biology, biochemistry, advancements in technological approaches, and discovery of new/novel enzymes, has revolutionized the application potential of enzymes in a variety of food industries including the bakery. World over people want their foods to be free of chemical preservatives and additives, therefore, the role of enzymes in potentially replacing the chemicals is very imperative. Application of enzymes in bakery not only enhances the dough properties such as, gas retention, crumb softness, water absorption capacity, and others but improves the nutritional status of products. Microbial sources of enzymes offer multiple advantages over plants and animals. Microbial enzymes from diverse resources have been reported for usage in bread making. A wide array of microbial enzymes viz. xylanases, phytases, α-amylases, proteases, cellulases, glucose oxidases, lipase and others have been reported to enhance the nutritional, sensory and other desirable properties of bread. Current article presents recent developments on application of enzymes for improvement of bread quality.
The objective of this study was to produce oxidatively and physically stable 70% fish oil-in-water emulsions by combined use of sodium caseinate (CAS), commercial diacetyl tartaric acid esters of mono- and diglycerides (DATEM), and modified DATEM. First, optimal formula was determined using DATEM and CAS. Subsequently, modified DATEMs (DATEM C12 and DATEM C14) were designed for investigating both the effects of different alkyl chain lengths and caffeic acid conjugation to the emulsifier on physical and oxidative stability of the emulsions. Emulsions produced with modified DATEMs showed better oxidative stability compared to emulsion with commercial DATEM plus equivalent amount of free caffeic acid, confirming the advantage of having antioxidant covalently attached to the emulsifier. Results indicated that DATEM_C14 replaced more CAS compared to DATEM_C12 from the interface in 70% fish oil-in-water emulsion. Emulsions produced with DATEM_C14 had significantly decreased amounts of primary and secondary oxidation products compared to emulsions with DATEM_C12.
The role of the main functional ingredients used in breadmaking are considered for the main groups of breadmaking processes. The physical and chemical character of fats, emulsifiers, oxidising agents, enzymes, preservatives and other functional ingredients are considered. Their contributions to the formation of a stable foam, dough rheology, gas retention in the dough final bread quality are discussed for a range of fermented products and breadmaking processes. The nature of the yeast microorganism and its manufacture of baker’s yeast are summarised and the main available types identified. The production of carbon dioxide gas in bread dough by baker’s yeast is detailed along with consideration of the factors which affect its gas production potential. The use of spontaneous fermentation using starter doughs is considered.
The aim of this study was to evaluate the effects of two emulsifiers, sodium stearoyl‐2‐lactylate ( SSL ) and diacetyl tartaric acid esters of mono and diglycerides ( DATEM ) on the physical and textural characteristics of gluten‐free ( GF ) cheese bread and the influence they have during storage. DATEM and SSL in percentages of 0.5 and 1.0 were added based on the amount of cheese in the formula. The dough behaved as a viscoelastic solid, adjusting itself to a model consisting of three Maxwell elements with a spring in parallel. The results indicate that emulsifiers had no significant effect on dough rheology. The emulsifiers affected the physical and textural characteristics of GF cheese bread. The height, diameter and specific volume of the samples decreased with higher concentrations of emulsifiers in the formula, while the yield and crumb hardness increased. Crust fracture and crumb hardness of samples increased during storage, thus the emulsifiers did not control product aging.
Practical Applications
Large‐scale production and the rise in consumers that demand good‐quality GF products have brought about the need to use food additives, such as emulsifiers, which are used as antiaging agents in bakery products by increasing their shelf life. Few studies have been carried out into the use of emulsifiers in GF products. For this reason, it is considered of great importance to evaluate the effect that these additives have on GF cheese bread, which is made by blending mainly sour cassava starch, water or milk, cheese, salt, sugar and fat. This product has a large market in S outh A merica and could be an alternative for celiac patients in that region.
The formation of starch-inclusion complexes has been investigated under conditions comparable to food processing operations. The following flavor model-substances were used: 1-hexanol, 1-octanol, 1-decanol, decanal, 1-menthol, 1-menthone, limonene and pinene. The experiments were conducted under equilibrium conditions. Potato starch proved to be a most suitable compound, followed by rice starch, corn starch and potato amylose. The complex-formation of potato amylose was disturbed by retrograation.
The action of polyoxyethylene stearate in preventing the hardening of bread on aging is discussed and ascribed to two functions: (a) a very efficient “shortening” action which softens the bread crumb, and (b) a depression of the swelling and swelling power of starch gels which, in effect, causes the starch to be partially stale, the bread therefore does not change so rapidly with age.The two functions may be observed separately by (a) the usual shortenings common to bakery practice which do not cause a hardening of the starch, and (b) stearic acid which has a depressant action on the swelling of starch but little or no shortening properties.
The interaction between monostearin and amylose in an aqueous environment has been studied by Raman spectroscopy. A perdeuterated lipid was used to follow the C-D stretching vibrations. The hydrocarbon chain conformation inside the amylose helix seems to be ordered as in the crystalline state, and the geometry of the amylose V-form of this complex corresponds to nearly three turns of the helix per hydrocarbon chain. The maximal amount of monoglyceride in the complex (1: 5 monoglyceride: amylose) obtained experimentally, indicates that not the whole chain is in the average involved in complex formation.
Untersuchung des Amylose-Monoglyceridkomplexes durch Raman-Spektroskopie.
Die Wechselwirkung zwischen Monostearin und Amylose in wäßrigem Medium wurde mit Hilfe der Raman-Spektroskopie untersucht. Zur Beobachtung der C-D-Spannungsvibrationen wurde ein überdeuterisiertes Lipid verwendet. Die Konformation der Kohlenwasserstoffkette innerhalb der Amylosehelix scheint wie im kristallinen Zustand geordnet zu sein, und die Geometrie der Amylose-V-Form dieses Komplexes entspricht annähernd drei Windungen der Helix je Kohlenwasserstoffkette. Die maximale Monoglyceridmenge im Komplex (Monoglycerid: Amylose =1:5), die experimentell ermittelt wurde, zeigt, daß im Durchschnitt keine ganze Kette in die Komplexbildung einbezogen ist.
Components of various food emulsifiers distilled monoglycerides (E 471) sodium stearoyllactylate (E 481), calcium stearoyllactylate (E 482), diacetyltartaric acid esters of mono- and diglycerides (E 472 e) and mixed acetic and tartaric acid esters of mono- and diglycerides (E 472 f), have been separated analytically and on a semi-preparative basis by high-performance liquid chromatography. The various products were identified by off-line high-resolution mass spectrometry.
Retardation of bread staling has historically been an important economic consideration that has resulted in numerous scientific investigations. This review attempts to summarize the history of bread staling beliefs and practices. A major portion deals with factors that have been reported to influence the rate of bread staling. Other areas discussed include staling theories, methods employed to measure staling changes, and nutritional considerations associated with the staling phenomenon.
Es werden die Auswirkungen der Zustze von Fettsuren (C4 bis C22), Fettsurederivaten und einigen Emulgatoren (0,5 bis 3% bezogen auf Mehl) auf die Eigenschaften eines Weizenmehlteiges mittels Valorigraph untersucht. Technologisch bedeutsame Auswirkungen auf die Wasseraufnahme und das Valorigramm ergaben sich bereits bei 0,5 bis 2%igem Zusatz mit z. T. bemerkenswerten Unterschieden in Abhngigkeit von Kettenlnge, Schmelzpunkt oder Sttigungsgrad. Eine starke Senkung der Wasseraufnahme bewirkten insbesondere Capron-, Caprin- und Ölsure, die ebenso wie Erucasure mit zunehmender Knetzeit eine Erhöhung der Teigkonsistenz bewirkten. Es werden spezifische hydrophobe Wechselwirkungen mit den Mehlproteinen in Abhngigkeit von der Struktur der Lipoide vermutet.
The influence of monoglycerides (DGMS), stearoyl‐2‐lactylates (CSL, SSL), and diacetylated tartaric acid esters of monoglycerides (DATE) on amylograph curves of various starches has been investigated. DGMS gave the greatest increase in pasting temperature of wheat and tapioca starch, followed by SSL, CSL and DATE. The pasting temperature of corn and potato starch was less affected by these emulsifiers. Peak viscosity of wheat starch in distilled water was increased by all emulsifiers, and was decreased in tapioca and potato starch.
Both pasting temperature and peak viscosity were strongly influenced by variations in pH, and were to some extent also dependent on ion concentration. In hard tap water the peak viscosity was slightly decreased by the anionic emulsifiers (SSL > CSL > DATE), due to the presence of Ca ⁺⁺ and Mg ⁺⁺ ions, while DGMS gave a higher peak viscosity than in distilled water. DATE seems to be more sensitive to variations in pH or ion concentration than the other emulsifiers.
Molecular conformation of amylose in the presence of surfactants was studied. The intrinsic viscosity of neutral, aqueous salt amylose solutions decreased slightly, indicating that surfactants enter into the helical cavity of amylose molecules. Helical conformation of amylose is the most important factor in binding surfactants by starch. The amylose-surfacant complex seriously impedes β-amylolytic degradation of amylose. It was demonstrated by thin-layer chromatography that amylose-surfactant complexes were mainly responsible for the decreased maltose production. Studies of iodine-staining properties, potentiometric titration, and β-amylolysis showed that the loss of blue color results from surfactants occupying some of the helical cavity of amylose molecule that otherwise would be filled by iodine. The degree of insolubility of amylose-surfactant complex in water varied from one surfactants to another.
Die Wirkung von Tensiden auf Stärke in einem Modellsystem.
Die molekulare Konformation von Amylose in Gegenwart von Tensiden wurde untersucht. Die innere Viskosität neutraler wäßriger Salz-Amyloselösungen verringerte sich etwas, ein Hinweis darauf, daß Tenside in das Innere der Helix von Amylosemolekülen eintreten. Die helixartige Konformation der Amylose ist der wichtigste Faktor bei der Bindung von Tensiden durch Stärke. Der Amylose-Tensidkomplex behindert stark den β-amylolytischen Abbau von Amylose. Durch Dünnschichtchromatographie wurde gezeigt, daß die Amylose-Tensidkomplexe für die verminderte Maltoseproduktion verantwortlich sind. Untersuchungen der Iodfärbungseigenschaften, der potentiometrischen Titration und der β-Amylolyse zeigten, daß die Verringerung der Blaufärbung daraus resultiert, daß die Tenside einen Teil des Helix-Hohlraums des Amylosemoleküls besetzen, der sonst durch lod angefüllt sein würde. Der Grad der Unlöslichkeit des Amylose-Tensidkomplexes in Wasser ändert sich von einem Tensid zum anderen.
Binding of lipids and added fats increased as more work was applied to wheat-flour doughs mixed under nitrogen. Bound-lipid levels were lower in doughs mixed in air than in those mixed in nitrogen and increase in work input had little effect on the level of bound lipid in the former. The presence of DATEM emulsifier (diacetyl tartaric esters of mono- and diglycerides) had little effect on the air-mixed doughs, but brought about a considerable reduction in lipid binding in the doughs mixed under nitrogen. It is known that DATEM emulsifiers have profound effects on dough and bread properties and it is suggested that one effect of these emulsifiers is to maintain a pool of free lipid in the dough.
The hydrodynamic behaviour of amylose in dilute solution has been examined in detail. Evidence for, and against, the existence in aqueous solution of a conformation which is predominantly helical in character is critically discussed. Proper interpretation of the solution behaviour of amylose shows that the molecule is a statistical, or random, coil having no helical content in neutral, aqueous solution. In such solutions, the presence of complexing agents causes a coil-to-helical in character is critically discussed. Proper interpretation of the solution behaviour of in the presence of salt represents a change from random coil to helix, and not as hitherto suggested, a helix-to-coil transition.
Undamaged wheat starch granules were treated in water at 50°C for 72 hours, and their properties then compared with those of the parent starch before and after gelatinization. Some of their attributes suggest that little alteration has occurred, but changes in others indicate that the internal structure of the granule has been modified, increasing its heterogeneity in some respects, but reducing it in others. In particular, gelatinization occurs at a higher but much more sharply defined temperature as compared with the range of temperatures shown by the mixture of untreated granules.
The reaction of sucrose monostearate (SMS) with starches and starch fractions is similar to that of various substances with ‘antistaling’ activity with starch. SMS forms an insoluble complex with starches and competitively inhibits the reaction of iodine with amylose. Wheat starch granules adsorb SMS and it is suggested that the formation of an insoluble complex on the surface of the granules may play a part in the ‘antistaling’ activity of SMS.
An attempt has been made to deduce a theoretical equation describing the firming processes accompanying the ageing of the crumb of bread. The model proposed is based on separate contributions by the starch and gluten components. In the case of the starch, firming was considered to be due to development of regions of crystallinity within the physically discrete granules. With the structurally continuous gluten fraction, the firming process was attributed to the migration of water (at one time forming part of the structure of the protein) to the starch. The natural ratio of starch to gluten (6:1) in wheat flour ensures that the firming of the continuous phase, resulting from the previously established moisture re-distribution, together with the retrogradation of the starch, more than compensate for the slight softening of the starch caused by the small relative increase in its moisture level.
Five emulsifier combinations as well as hydrogenated vegetable shortening and unemulsified oil controls were tested in a research cake formula. Water loss and temperatures were monitored continuously during baking in a specially constructed environmental oven. Both the water loss rate and rate of temperature increase were depressed in the temperature ranges associated with starch gelatinization. The degree of depression was related to the emulsification system. Granule swelling as observed by scanning electron microscopy of the crumb was not greatly different, but the characteristics of the inter-granule matrix appeared to be related to the concentration of emulsifier.
Saturated monoglycerides were prepared in six different physical states: aqueous gels, at pH 6.8 and pH 7.3; a hydrate, aqueous and freezedried; a spray-crystallized powder; and a mono-/diglyceride emulsion. Their anti-firming effects in Danish white bread differed greatly, and were found to be related to their ability to form insoluble complex with amylose. the results show the need for hydration of monoglycerides prior to their use. the alpha-crystalline gel (pH 6.8) gave the highest complexing index with amylose and also the best anti-firming effect in bread.
Starting with a typical baker's dough, a model system was constructed in order to examine whether moisture re-distributed itself between the two principal components, gluten and starch, of crumb during ageing. Separation of the components of dough was achieved by ultra-centrifugation. It was estimated that up to 30% of the moisture associated with the gluten fraction, migrated to the starch during 120 h of storage of the baked system at 25°c. The rate of migration decreased approximately exponentially with time. Moisture from the gluten was also found to migrate to the starch during baking, but at an accelerated rate. The rate of moisture migration in the model system, both at 100 and 25°c, was consistent with a diffusion-controlled process involving migration of the gluten-released moisture to the gluten-starch interface. Experimental results show that staling of bread involves (in addition to the generally accepted retrogradation of the starch) an irreversible modification in the water structure of the gluten, leading to the formation of labile water, which becomes available for absorption by the incompletely gelatinised starch. Since the gluten forms the continuous matrix of the crumb, the modification results in a rigidification or firming process.
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.
1.
Whrend sich aus Mehl nach dem SchwereSinkverfahren in Benzol/Tetrachlorkohlenstoff als Suspensionsflssigkeit nur das freie Zwickelprotein im Mehl isolieren lt, wird durch Mahlung des Mehles vor der Sedimentierung in einer Kugelmhle zwecks Zerstrung der Endospermteile das gesamte Zwickelprotein sowie endospermfreies Haftprotein/Strke zugnglich.
2.
Fr die Trennung beider Proteinkomplexe ist ein Differential-Verfahren ausgearbeitet worden, das die Ausbeute an beiden Komplexen annhernd quantitativ zu ermitteln gestattet.
3.
Zwickelprotein und Haftprotein/Strke wurden elektronenoptisch und rntgenographisch charakterisiert.
4.
Durch Oberflchenbestimmungen nach der Argon-Methode und mittels statistischer Auszhlung wurden Oberflchen- und Grenzflchenverhltnisse in Mehl und seinen Komponenten betrachtet.
5.
Durch Aufteilung der lipoiden Phase des Mehles in Fett und Lipophosphatit ist die Bedeutung des Lipophosphatits fr die Hydratations- und Plastizierungsvorgnge bei Mehl und Teig experimentell nachgewiesen worden.
Pulsed nuclear magnetic reasonance (NMR) measurements were made on freeze-dried emulsions containing fat and protein. It was
demonstrated that this method can be used to determine the degree of lipid-protein interaction in the samples. Interaction
is maximized near the isoelectric range of the protein, which supports the theory that hydrophobic interactions are predominant.
Triglycerides and fatty methyl esters interact to nearly the same degree as do free fatty acids, which indicates that the
carboxylate group plays a minor role in interaction. Degree of interaction increases when the emulsions are homogenized at
higher pressures. There is an inverse relationship between interaction and foamability of the rehydrated emulsion suggesting
that less protein is available for film formation after interaction. In addition, fat-protein interaction was shown to protect
the protein from heat denaturation. These pulsed NMR measurements may represent an approach toward a better understanding
of lipidprotein interactions in food systems.
Staling, as it is applied to bakery foods, is a generic term covering a number of changes that occur in the products during normal storage. Consumers judge staleness by direct perception, which provides a subjective estimate that represents an unconscious integration of many factors. This review will discuss the main components of staling: (1) physicochemical changes of bread and related products (firming and texture deterioration of crumb and loss of crispness of crust) and (2) flavor changes. Section I will cover current theories of changes of firming and textural changes. The starch component of flour is generally considered to be responsible for these staling reactions. Consequently, the physicochemical involvement of amylose, amylopectin in these reactions will be fully discussed and current evidence supporting these theories (rheological, chemical, X-rays) will be given. Interactions of starch and surface active agents and other complexing compounds will be presented in Section II. In Section III, contribution of minor flour components and bakery food ingredients will be evaluated. Section IV will focus on organoleptic deterioration of products, presenting flavor changes that were observed during staling bread. Section V will discuss structural changes of breads caused by enzymolysis during bread production and storage as related to staling. Following the theoretical section (Sections I to V), Section VI will focus on practical control of staling. This discussion will cover the following factors: formulation, surfactants, enzymes, storage, freezing, and packaging.
Photocopy. Ann Arbor, Mich. : University Microfilms International, 1980. -- 21 cm. Thesis -- Kansas State University. Bibliography: leaves 99-109.
FOLLOWING an observation that sucrose stearate, a compound claimed to have anti-staling activity, precipitated starch from solution (to be published), the study was extended to other substances known to have anti-staling properties.
Technologie der Brotherstellung
- L. J. Auermann