Soft food thickener and soft food with such thickener

Abstract

A soft food thickener is disclosed as including a gel-forming and water-binding agent, a starchy polysaccharide, a high-temperature solidification and shape retention agent, and a viscosity stabilizing and shear-resistant thickening agent.

Description

- 1 - Soft Food Thickener and Soft Food with such Thickener Field of the Invention This invention relates to a soft food thickener and soft food including such a soft food thickener. Background of the Invention 5 The existing soft food thickeners, and thus, soft food made of such thickeners, suffer from several long‑standing limitations, including: 1. Collapse and melting during high‑temperature reheating: Existing thickeners cannot maintain shape above 80-85 °C. Therefore, existing soft food melt or deform during steaming or reheating; such food must be served warm, not hot;10 and molded shapes (e.g., vegetables, abalone, meat slices) cannot be preserved. 2. Poor freeze–thaw stability and water syneresis: Most commercially available soft food thickeners release water after freezing and thawing, produce wet, unstable textures, lose shape integrity, and / or require fresh preparation instead of frozen storage15 3. Inability to produce International Dysphagia Diet Standardisation Initiative (IDDSI) Level 4-7 structured soft food: Prior art thickeners are mainly designed for beverages (IDDSI Levels 1-3), cannot create stable Level 4-7 foods, fail to hold molded shapes, and cannot mimic natural food appearance20 4. High caloric contribution of conventional polysaccharide thickeners: Traditional thickeners rely heavily on digestible polysaccharides, leading to high caloric load and increased metabolic burden, and thus unsuitable for elderly or calorie‑restricted diets. 5. Lack of ingredient synergy for high‑performance gelation: 25 Prior art systems typically use single‑function polysaccharides, with no mechanism for high‑temperature solidification. It is thus an object of the present invention to provide a soft food thickener and a soft food including such a soft food thickener for at least mitigating at least one of the above 30 shortcomings or at least providing a useful alterative to the trade and public. Summary of the Invention According to a first aspect of the present invention, there is provided a soft food thickener HK 30134887 A - 2 - including a gel-forming and water-binding agent, a starchy polysaccharide, a high-temperature solidification and shape retention agent, and a viscosity stabilizing and shear-resistant thickening agent. According to a second aspect of the present invention, there is provided a soft food including 5 a soft food thickener which includes a gel-forming and water-binding agent, a starchy polysaccharide, a high-temperature solidification and shape retention agent, and a viscosity stabilizing and shear-resistant thickening agent. Description of the Embodiments 10 The present invention provides a thermally stable, freeze-thaw-resistant polysaccharide-fiber thickener for shape‑retaining soft food, having a novel polysaccharide-fiber matrix composed primarily of soluble dietary fiber. This matrix binds water efficiently without syneresis after freezing and thawing, delivers less than half the caloric contribution of conventional thickeners, and provides superior textural stability across a wide range of processing conditions. The soft 15 food thickener according to this invention enables the production of soft foods - such as molded vegetable pieces, abalone slices, or customized shapes - that preserve their original form and sensory appeal. The invention therefore represents a next‑generation solution for safe, visually appealing, and nutritionally appropriate soft‑food products designed for elderly individuals and other populations requiring modified‑texture diets. 20 Broadly stated, the soft food thickener according to the present invention includes: - 35-55 wt.% (preferably 40-50 wt.%) of a gel-forming and water-binding agent (such as at least one of konjac glucomannan, gellan gum (which may be a low-acyl gellan gum or a high-acyl gellan gum), agar, locust bean gum and tara gum);25 - 25-45 wt.% (preferably 30-40 wt.%) of a starchy polysaccharides (such as dextrin); - 3-12 wt.% (preferably 4-9 wt.%) of a high-temperature solidification and shape retention agent (such as at least one of inulin, resistant dextrin, partially hydrolyzed guar gum and oat β‑glucan); and - 2-10 wt.% (preferably 3-8 wt.%) of a viscosity stabilizing and shear-resistant thickening30 agent (such as at least one of xanthan gum and guar gum). In an embodiment, konjac glucomannan (KGM) constitutes the principal structural polymer within the soft food thickener according to the present invention. As a high‑molecular‑weight, HK 30134887 A - 3 - linear β‑1,4‑linked glucomannan, it exhibits exceptional hydration and gel‑forming capabilities. When dispersed in water, KGM undergoes rapid chain expansion and forms a highly viscous, entangled network through: - hydrogen bonding between hydroxyl groups along the polysaccharide backbone, - chain entanglement and coil‑to‑extended‑chain transitions, and 5 - formation of a hydrated, three‑dimensional matrix capable of immobilizing free water. These molecular interactions provide: - primary gel strength and mechanical rigidity, - high water‑binding capacity, reducing syneresis, 10 - elasticity and shape retention, essential for molded soft‑food structures, and - thermal resilience, maintaining network integrity during heating and reheating. Konjac glucomannan undergoes the following several physicochemical changes that contribute to the performance of the invention: 15 - hydration‑induced chain expansion, - thermally-assisted gel reinforcement, - freeze–thaw stability mechanism, and - synergistic interaction with co‑polymers. 20 In an embodiment, dextrin serves to enhance freeze-thaw stability and contributes to structural resilience. In particular, dextrin functions as a structural modifier within the multi‑component gel system. As a partially hydrolyzed starch derivative composed of short to medium‑chain α‑1,4 / α‑1,6 glucan fragments, dextrin exhibits controlled solubility and moderate water‑binding capacity. These characteristics allow dextrin to: 25 - enhance freeze-thaw stability by minimizing ice‑crystal growth and reducing mechanical disruption of the gel matrix, - improve internal cohesion, reducing fracture propagation under compression, - increase elastic resilience, enabling the gel to recover shape after deformation, and - moderate the rigidity of konjac‑based gels, preventing overly firm or brittle textures. 30 Dextrin undergoes the following several physicochemical behaviors that directly contribute to the performance of the invention: - hydration and matrix penetration, HK 30134887 A - 4 - - cryoprotective behavior during freezing, - thermal stabilization and plasticization, and - modulation of water distribution. Dextrin also plays a critical role in reinforcing and modifying the konjac‑based gel network. 5 Dextrin chains interpenetrate the konjac lattice, filling structural voids and reducing brittleness. This creates a composite gel with improved flexibility, resilience, and reduced fracture tendency. Dextrin enhances water immobilization and contributes to a more uniform gel density. Dextrin also moderates viscosity and prevents excessive shear‑thickening, improving processability. The combined effect is a synergistic gelation system with superior freeze–thaw 10 stability, thermal tolerance, and mechanical robustness compared to systems lacking dextrin. The soluble dietary fiber component functions as the high‑temperature solidifying agent within the multi‑polymer gel system. Owing to its branched or linear polysaccharide structure - typically comprising β‑linked or mixed‑linkage glucose, galactose, or arabinose units - it 15 exhibits controlled hydration, thermal thickening behavior, and network‑reinforcing capabilities. Within the composition, soluble dietary fiber provides: - shape retention at elevated temperatures up to more than 90 °C, - thermal gelation and viscosity enhancement, preventing matrix collapse during cooking, - increased firmness and bite, without imparting excessive hardness or brittleness, and 20 - improved structural continuity, particularly under thermal stress. Soluble dietary fiber undergoes several key physicochemical transitions that directly contribute to the invention’s high‑temperature performance: - thermal thickening and partial gelation, 25 - formation of secondary cross‑linking domains, - water immobilization and thermal moisture control, and - structural integration with konjac and dextrin. Soluble dietary fiber plays a critical role in the multi‑component synergy: 30 - with konjac glucomannan: provides thermal reinforcement when konjac softens at high temperatures, preventing structural collapse, - with dextrin: enhances freeze–thaw stability and contributes to a more uniform, cohesive gel matrix, and HK 30134887 A - 5 - - with xanthan gum: supports viscosity control and stabilizes shear‑dependent flow properties during processing. Together, these interactions create a thermally resilient, dual‑phase gelation system capable of maintaining structural integrity during freezing, thawing, cooking, and reheating. 5 In an embodiment of the present invention, xanthan gum functions as the principal viscosity stabilizer and shear‑resistant rheology modifier within the multi‑polymer gel system. As an anionic, high‑molecular‑weight heteropolysaccharide composed of a β‑1,4‑D‑glucose backbone with trisaccharide side chains, xanthan exhibits exceptional hydration, pseudoplastic 10 flow behavior, and thermal stability. Within the composition, xanthan gum provides: - high shear‑thinning control, preventing structural breakdown during mixing, pumping, or molding, - uniform viscosity distribution, ensuring consistent mouthfeel and textural uniformity, - suspension stability, preventing phase separation of dispersed solids or co‑polymers, and 15 - enhanced elastic–viscous balance, contributing to cohesive, shape‑retaining soft‑food structures. Xanthan gum undergoes several key physicochemical transitions that directly contribute to the invention’s stability, processability, and final texture: 20 - hydration and helical conformation stabilization, - pseudoplastic (shear‑thinning) behavior, - thermal stability and high‑temperature viscosity retention, - electrostatic and hydrogen‑bond interactions with co‑polymers 25 Xanthan gum plays a critical role in the overall synergy of the soft food thickener according to the present invention: - with konjac glucomannan: forms a cooperative gel network through hydrogen bonding and conformational compatibility, yielding enhanced elasticity, firmness, and structural resilience,30 - with dextrin: stabilizes dextrin dispersion and prevents localized viscosity gradients, ensuring uniform gel formation, and - with soluble dietary fiber: supports high‑temperature viscosity retention and contributes to the dual‑phase thermal stabilization mechanism. HK 30134887 A - 6 - Together, these interactions produce a highly stable, shear‑resistant, and thermally robust gel system suitable for IDDSI Level 4–7 soft‑food applications. The four‑component composition forms a multi‑layered, interpenetrating polymer network 5 (IPN) in which each hydrocolloid undergoes distinct chemical and physical transitions that collectively produce a high‑performance gel system. When combined, the components forming the soft food thickener according to the present invention assemble into a hierarchical gel architecture comprising: 10 - primary network (konjac-xanthan backbone): hydrogen bonding, coil–helix transitions, and polymer entanglement create a strong elastic-viscous framework, this backbone providing the fundamental load‑bearing structure, - secondary reinforcement (dextrin interpenetration): hydrated dextrin chains diffuse into the primary network, filling micro‑voids and increasing internal cohesion, reducing brittleness15 and enhances freeze–thaw stability, - thermal stabilization layer (soluble dietary fiber structuring): at elevated temperatures, soluble fibers undergo partial gelation and viscosity increase, and form additional cross‑linking domains that prevent thermal collapse and maintain shape at 95 °C, - water‑management sub‑network: all polymers contribute to water immobilization through 20 hydration shells and hydrogen bonding. This multi‑polymer water‑binding system prevents syneresis during freezing, thawing, and reheating. In an embodiment, the soft food thickener may incorporate optional additives, such as natural colours, flavour enhancers, nutritional fortifiers (such as protein, vitamins, minerals), and / or 25 antioxidants for shelf‑life extension. In one embodiment, the appropriate weight of each of the components forming the soft food thickener according to the present invention is weighed and poured into a container, well mixed and then blended to form the thickener. The soft food thickener may be further treated to render 30 it in the form of powder, granules, pre-hydrated gel and ready-to-use paste. Alternatively, the components may be formed into the soft food thickener according to the present invention by pre‑gelatinizing the mixture, using enzymatic cross‑linking, and / or using HK 30134887 A - 7 - high‑pressure processing, to achieve similar stability. In one embodiment, forming and serving soft food with a soft food thickener according to the present invention involves the following steps: - pre-cooking the food ingredients, 5 - mashing or pureeing the pre-cooked food ingredients, - blending the meshed or pureed food ingredients with soft food thickener according to the present invention, and, optionally, with soup, oils, and / or seasonings, - heating the blend to over 75 oC, - optionally, moulding the heated (then cooled) blend, 10 - cold storage (≤ 4 oC or ≤ -18 oC), and - reheating ( 75 oC). The present invention delivers several critical advantages that existing soft food thickeners cannot achieve. These advantages arise from the unique synergy of the components forming 15 the soft food thickener according to the present invention - combined in a way that produces performance characteristics not taught or suggested in the prior art. 1. Superior high‑temperature stability (up to higher than 90 °C) Soft food formed with soft food thickener according to the present invention maintains its gel structure and shape during steaming or reheating at 95 °C, whereas prior art thickeners20 typically collapse at 80-85 °C. As such, soft foods can finally be served hot, not just warm. Molded shapes (vegetables, abalone, meat slices) remain intact. Such also enables safe reheating in hospitals, elderly homes, and commercial kitchens. Table 1 below shows gel stability comparison of a soft food thickener according to an 25 embodiment of the present invention with two existing soft food thickeners: Table 1 Time (min) Internal Temperature (oC) Internal Temperature (oC) Internal Temperature (oC) Thickener A Thickener B Thickener of the Present Invention 0 0.6 0.6 0.8 1 1.4 1.8 1.2 2 1.9 2.2 1.8 HK 30134887 A - 8 - It can be seen that while the prior art soft food thickeners melted to collapse starting from around 70 oC to 80 oC respectively, the soft food thickener according to the present invention remained stable at above 90 oC and with no syneresis. 2. Exceptional freeze-thaw stability with no (or at least minimal) syneresis 5 Soft food formed with soft food thickener according to the present invention prevents water separation after freezing and thawing, maintaining a uniform, stable texture. As such, soft foods can be produced, frozen, stored, transported, and reheated without quality loss. The “watery” appearance common in existing soft foods can be eliminated. This invention also supports large‑scale production of frozen soft‑food meals. 10 3. Ability to produce IDDSI level 4-7 structured soft foods Soft food thickener according to the present invention can used to form soft food of a full range of soft‑food textures - from pureed (IDDSI Level 4) to easy‑to‑chew (IDDSI Level 7) - while retaining shape after high heat treatment. This enables visually appealing, realistic soft foods for elderly users, supports personalized texture modification for 15 dysphagia management, and expands product applications beyond beverages, while still retaining the ability to product IDDSI level 1-3 foods. 4. Low‑calorie, fiber‑dominant formulation Soft food thickeners according to the present invention contribute less than 50% of the calories of conventional polysaccharide thickeners. Such is thus suitable for elderly20 individuals with calorie‑restricted diets, reduces metabolic load while maintaining 3 4.6 4.8 4.4 4 8.2 8.2 7.4 5 14.8 14.8 13.9 6 23.6 23.6 22.5 7 32.6 32.6 31.6 8 37.8 37.8 36.7 9 48.3 48.3 47.6 10 57.4 57.4 56.4 11 67.8 67.8 66.9 12 73.5 melted 73.5 72.9 13 79.4 melted 79.4 78.9 14 84.2 melted 84.2 melted 83.6 15 90.5 melted 90.5 melted 90.2 17 95.2 melted 95.2 melted 95.3 20 99.2 melted 99.1 melted 99.0 HK 30134887 A - 9 - nutritional fiber intake, and supports healthier soft‑food product lines. 5. Eliminates the need for additional stabilizers or modified starches Soft food thickeners according to the present invention achieve all functional properties without modified starches, protein binders, heat‑activated gelling agents, and chemical cross‑linkers. Such thus allows cleaner label, lower cost, simpler formulation and better5 nutritional profile. 6. Maintains neutral taste, color, and sensory smoothness Soft food thickeners according to the present invention do not alter the flavor or appearance of the food and produces a smooth, non‑grainy texture. Such therefore enhances acceptance among elderly users, supports premium soft‑food products and allows natural food flavors10 to remain dominant. It should be understood that the above only illustrates examples whereby the present invention may be carried out, and that various modifications and / or alterations may be made thereto without departing from the spirit of the invention. 15 It should also be understood that certain features of the invention, which are, for clarity, described in the context of separate embodiments, may be provided in combination in a single embodiment. Conversely, various features of the invention which are, for brevity, described in the context of a single embodiment, may also be provided separately or in any appropriate 20 sub-combinations. HK 30134887 A - 1 - CLAIMS: 1. A soft food thickener including a gel-forming and water-binding agent, a starchy polysaccharide, a high-temperature solidification and shape retention agent, and a viscosity stabilizing and shear-resistant thickening agent. 5 2. The thickener of Claim 1, wherein said at least gel-forming and water-binding agent includes at least one of konjac glucomannan, gellan gum, agar, locust bean gum and tara gum. 3. The thickener of Claim 2, wherein said gellan gum is a low-acyl gellan gum or a high-10 acyl gellan gum. 4. The thickener of Claim 1, wherein said starchy polysaccharide is dextrin. 5. The thickener of Claim 1, wherein said high-temperature solidification and shape 15 retention agent includes a soluble fiber. 6. The thickener of Claim 5, wherein said soluble fiber includes at least one of inulin, resistant dextrin, partially hydrolyzed guar gum and oat β‑glucan. 20 7. The thickener of Claim 1, wherein said viscosity stabilizing and shear-resistant thickening agent includes at least one of xanthan gum and guar gum. 8. The thickener of Claim 1, wherein said gel-forming and water-binding agent is of 35-55 wt.%.25 9. The thickener of Claim 1, wherein said starchy polysaccharide is of 25-45 wt.%. 10. The thickener of Claim 1, wherein said high-temperature solidification and shape retention agent is of 3-12 wt.%.30 11. The thickener of Claim 1, wherein said viscosity stabilizing and shear-resistant thickening agent is of 2-10 wt.%. HK 30134887 A - 2 - 12. The thickener of Claim 1, wherein said thickener is in the form of powder, granules, pre- hydrated gel or ready-to-use paste. 13. The thickener of Claim 1, further including at least one of a natural colour, flavour enhancer, nutritional fortifier and an antioxidant.5 14. A soft food including a soft food thickener according to Claim 1. 15. The soft food of Claim 13, wherein said soft food is of a structure of from International Dysphagia Diet Standardisation Initiative (IDDSI) level 4 to level 7.10 16. The soft food of Claim 14, wherein said soft food is in a drinkable form of IDDSI level 1 to level 3. 17. The soft food of claim 14, wherein said soft food is adapted to maintain a gel structure 15 and shape during steaming and reheating at up to 95 oC. 18. The soft food of Claim 14, wherein said soft food is adapted to maintain a stable structure after freezing and thawing. 20 HK 30134887 A