MODIFICATION OF RHEOLOGY OF SUGAR CONFECTIONERY

Abstract: The invention relates to sugar confectionery products. The invention provides a method of modifying the rheology, texture and physical chemistry of said products by the addition of small amounts of hydrocolloid to the confectionery product.

Description: MODIFICATION OF RHEO OGY OF SUGAR CONFECTIONERY The invention relates to sugar confectionery products. The invention provides a method of modifying the rheology, texture and physical chemistry of said products by manipulating the dynamic thermo-mechanical transitions in the sugar-water confectionery system. Sugar confectionery products contain a high concentration of sugars and other soluble solids and are generally characterised by a low moisture content. A common problem with such confectionery products is the occurrence of sugar crystallisation. Whilst desirable in some confections, such as in fondants and fudge, sugar crystallisation causes the undesirable effect of graining in other confectionery products, such as, hard- boiled sweets, toffees and caramel. Crystallisation is manifested as an unpleasant gritty texture. In hard-boiled sweets, graining is evident as a loss in clarity and flavour. It is accompanied by stickiness, starting at the surface and proceeding inwards. An important factor in the occurrence of sugar crystallisation is the balance of sugars in the product and, indeed, conventionally this has been used to control crystallisation. In the past, re-crystallisation in hard-boiled sweets and fondant centres was controlled by using cream of tartar and acetic acid to cause acid inversion of sucrose during cooking. Standardised invert sugar or, most commonly, glucose syrups are now conventionally used as 'doctors' to control crystallisation in confectionery. An understanding of mechanisms involved in sugar ciystalhsation is essential to the control of graining and shelf-life of sugar confectionery. A deterioration in other properties of sugar confectionery products is also noted during storage. Acceleration of graining may arise if moisture is picked up on the surface of the product, therefore, lowering the viscosity and glass transition temperature. Storage conditions that dehydrate the product may also result in the sucrose crystallising out. As a consequence, expensive moisture-proof packaging is often required. The present invention aims to control rheology, sugar crystallisation and texture in confectionery products, in particular, in confectionery products comprising a high content of sugars. The invention aims to provide confectionery products with a higher than average sugaπglucose ratio in order to improve cost effectiveness, but avoiding any associated increase in sugar crystallisation and loss of texture. The invention aims to increase the moisture holding capacity of a sugar confectionery product, particularly those having a high content of sugars, but still provide a confectionery product which has equivalent properties to a product having a lower moisture content. The invention aims to improve the storage properties of confectionery products, in particular, to prevent the deterioration in texture and properties (for example stickiness) of a high sugar content confectionery, such as, a hard-boiled product or pastille, which occurs when the confectionery is stored in a high humidity environment due to moisture pick up. The invention provides a method of modifying the texture and viscoelasticity of a confectionery product by the addition of a hydrocoUoid or a combination of hydrocolloids, in particular, a confectionery product comprising a high content of sugars. The present inventors have found that the addition of small amounts of a hydrocoUoid to a high sugar system will modify the glass transition temperature (Tg), modify or weaken the biopolymer associations and modify the rheological (viscoelasticity) properties of the product. For example, it has been found that agar gels formed in water are brittle, but when added to a very high sugar environment result in a rubbery deformable structure. The hydrocolloids have been found to cause an increase in the water holding capacity. It may be hypothesised that water is held by the hydrocoUoid to modify the Tg or water activity of the system. WhUst not wishing to be held by theory, it is believed to be the influence of hydrocoUoids on the sugar-water system and/or the influence of sugars in limited water on the behaviour of hydrocoUoids that influences this invention. Two physico-chemical concepts which are the subject of this invention are outlined below: 1: Rubbery viscous state Interchain association of geUing agents (biopolymers) is modified or might be prevented in the presence of sugars or other co-solutes such as sugar replacers, glycerol, flavouring compounds and carriers, colours, alcohol, acids and salts. In a high water system, addition of a geUing agent results in interchain association forming junction zones and a cross-linked network, resulting in a gel. However, in a system containing also a high level of sugars, the interchain association is modified, hindered by sugar-water interaction reduced mobnity and stearic hindrance, and junction zones may not form so readily. The stearic presence of hydrocolloids may confer stabUity in the dispersion of other components such as colours, flavours, acids, functional ingredients (herbs, minerals, vitamins, spices), fat, protein and inhibit sugar crystallisation. 2: Sugar-biopolymer glasses Addition of hydrocoUoid in a sugars-water system wiU change the Tg (glass transition temperature) versus moisture relationship, shifting the Tg curve towards higher moisture and possibly modifying the shape of the Tg curve. The confectionery product of the invention is preferably a high sugar content confectionery product, for example, selected from hard-boiled sweets, pastilles, caramel, hard candy, soft chews, toffees, gums and jellies etc. The confectionery product preferably comprises a high concentration of sugars, for example, preferably between 65 and 99% by weight. This will depend, however, on the confectionery. The confectionery product of the invention may comprise other solutes as well as sugar, for example, sugar replacers such as sorbitol, isomalt, mattitol, mannitol, lactitol, erythritol, glycerol, flavouring compounds, carriers, colours, alcohols, acids, such as, citric, lactic, malic, fumaric, tartaric, and salts. The sugar replacers may partially or completely replace the sugars in the confectionery product. Other ingredients may be present in an amount of from 0.1 to 5% by weight. Confectionery products are generally characterised by a low moisture content and a high content of soluble sohds. A glassy confectionery product modified in accordance with the invention may have a higher than average moisture content but retain desirable characteristics relating to texture and viscoelasticity. The invention preferably raises moisture content from typically about 2% towards about 10%. The hydrocoUoid used in the method of the invention may be any conventionally used geUing agent or biopolymer which influences the sugar-water system of the confectionery product. Suitable examples of hydrocoUoids include, but are not limited to carrageenans, gelatin, agar, pectins, maltodextrins, plant fibres, starches or combinations thereof. The hydrocoUoid is added to the confectionery product only in a small amount, for example in an amount of from 0.1 to 15%, preferably in an amount of from 1 to 5%. A particular advantage of the invention is that the hydrocoUoid may be used to replace gelatin where it is undesirable to have gelatin in a product, for example, due to dietary considerations. The invention further provides a glassy confectionery product modified by the addition of a small amount of a hydrocoUoid. The confectionery product preferably has a high content of sugars and has improved storage properties, has a reduced tendency to display sugar crystallisation, may have a higher ratio of sugaπglucose than in conventional products and has an increased moisture holding capacity without any detrimental affect to its texture and rheological properties. The method of the invention is applicable to all sugar confectionery types and to their various processes of preparation. The hydrocoUoid requires pre-hydration and dispersion in adequate water to ensure functionality. This may require modification to a particular recipe process according to type. The invention will now be illustrated according to the following examples which are not intended to be limiting. EXAMPLES Example 1 Caramel with hydrocoUoid stabilisation - Reduced Milk Protein (Cost) Flow Stability Novel Texture Recipe (Ingredient Proportions) % Glucose Syrup (42DE) 35.5 Sucrose 24 Vegetable Fat 20 Sweetened Skimmed Condensed Milk 10 Salt 0.2 Carrageenan 0.3 Water 10 100 Process • Disperse carrageenan in warm water (50°C) with high speed mixing. • Combine with all other ingredients in toffee boiling pan. • Boil to a final moisture content according to required texture (typically 10% residual H 2 O). • Cool and form. Example 2 Hard Candy with HydrocoUoid Moisture Sorption Tolerant Stability in Humid Conditions Recipe (Ingredients) % Glucose Syrup (42DE) 35 Sucrose 35 Maltodextrin (5DE) - Tapioca 5 Water 25 100 Process Dissolve maltodextrin in water at 50°C. Combine with all other ingredients in stirred vessel. Heat to 90°C to dissolve sucrose. Boil/evaporate to achieve a final moisture content of 3%. Cool and form. The invention provides a number of significant improvements and advantages as follows: Rubbery viscous state for example in chews, jellies, gums, toffee/caramel, liquorice, foams: 1 : Creating novel textures for confectionery products by controlling the degree of biopolymer interaction by manipulation of controlling factors. 2: To be able to match the texture of gelatin based confections using alternative biopolymer(s) through control of molecular behaviour in high sugar system. 3: Conferring dimensional stabUity in viscous confections by achieving a rigid molecular entanglement. Achieved instantaneously by temperature drop, avoiding the time dependant need for molecular re-arrangement. Hence, process time can be substantially reduced. 4: Create and stabUise a sugar confectionery emulsion gel in a rigid or semi-rigid biopolymer network, giving novel texture and flavour delivery and/or an alternative to use of added emulsifier(s) for cost or legal restriction (e.g. GMO) Sugar-biopolymer glasses 1 : A high moisture (up to 10% water content), relatively high water activity hard candy through addition of an amount of polysaccharide(s). Benefits are improved stability in humid condition and wider compatibUity in combination with other confectionery masses such as liquid fillings. 2: Inclusion of an amount of biopolymer in a hard candy to aUow the candy mass to absorb a significant uptake of moisture from its environment without textural degradation, thus benefiting shelf life and offering opportunities to downgrade expensive packaging. 3: Moisture-tolerant encapsulation of flavour and/or acid or other minor ingredients (as above) in a sugar glass matrix stabUised with biopolymer.

Claims: CLAIMS: 1. A method of modifying the viscoelasticity and glass transition temperature of a confectionery product by addition of a hydrocoUoid or combination of hydrocolloids to said confectionery product. 2. The method according to claim 1 wherein the confectionery product comprises a high sugars content or a high content of sugar replacers. 3. The method according to claim 1 or claim 2 wherein the confectionery product has a moisture content of up to 30%. 4. The method of any of claims 1 to 3 wherein the amount of hydrocoUoid added is from 0.1 to 15% . 5. The method of any of claims 1 to 3 wherein the hydrocoUoid is selected from carrageenans, agarose, pectins, gellan gum, starches and maltodextrans. 6. A sugar confectionery product which has been modified by the addition of a hydrocoUoid.

Inventors: ONG MEI HORNG, WHITEHOUSE ANDREW STEVE, ONG, MEI, HORNG, WHITEHOUSE, ANDREW, STEVE
Applicants: NESTLE SA, ONG MEI HORNG, WHITEHOUSE ANDREW STEVE, ONG, MEI, HORNG, SOCIETE DES PRODUITS NESTLE S.A., WHITEHOUSE, ANDREW, STEVE
Application year: 2001
Main classification: A23G3
IPC codes: A23G3