Sugar reduction without compromising sensory perception. An impossible dream?

ABSTRACT

Sugar reduction is a major technical challenge for the food industry to address in response to public health concerns regarding the amount of added sugars in foods. This paper reviews sweet taste perception, sensory methods to evaluate sugar reduction and the merits of different techniques available to reduce sugar content. The use of sugar substitutes (non-nutritive sweeteners, sugar alcohols, and fibres) can achieve the greatest magnitude of sugar and energy reduction, however bitter side tastes and varying temporal sweet profiles are common issues. The use of multisensory integration principles (particularly aroma) can be an effective approach to reduce sugar content, however the magnitude of sugar reduction is small. Innovation in food structure (modifying the sucrose distribution, serum release and fracture mechanics) offers a new way to reduce sugar without significant changes in food composition, however may be difficult to implement in food produced on a large scale. Gradual sugar reduction presents difficulties for food companies from a sales perspective if acceptability is compromised. Ultimately, a holistic approach where food manufacturers integrate a range of these techniques is likely to provide the best progress. However, substantial reduction of sugar in processed foods without compromising sensory properties may be an impossible dream.     

Invited review: Sugar reduction in dairy products

Sugar overconsumption continues to increase worldwide and contributes to multiple health-related issues. Dairy foods represent a large market, grossing more than $125 billion per year worldwide. Consumer demands for healthier products are leading to a large push for sugar reduction in dairy foods. Sugar plays an important role in dairy foods, not only in flavor but also in texture, color, and viscosity. Replacing sugar can have negative effects, making substitution inherently difficult. Natural and artificial nonnutritive sweeteners exist for sugar reduction. Natural nonnutritive sweeteners are popular, particularly for label appeal, but many consumers still prefer the taste of artificial nonnutritive sweeteners. Sweet taste perception can also be affected by texture of the food matrix and the presence of fat. Other sugar reduction techniques include hydrolysis of lactose, ultrafiltration, and direct reduction. This review will address the role of sugar, alternative sweeteners, and sugar reduction in ice cream, yogurt, and flavored milk.     

Sweet processed foods in Brazil: use of sugar and sweeteners,inclusion of sugar claims and impact on nutritional profile

This study characterised the main sweet beverages and food products marketed in Brazil regarding (i) the addition of sugar/sweeteners, (ii) nutritional profile and (iii) sugar claims. Results revealed that most of the beverages had added sweeteners, while food products were mainly sweetened with sugar. Moreover, >90% of the powdered products had added sweeteners. ‘Zero sugar’ (46%) and ‘light’ (55%) were the most common sugar claims in sugar-free and reduced-sugar products, respectively. Powdered products, soya drinks and baked products included claims less frequently. Regarding the nutritional profile, beverages with sugar substitution had a proportionally greater reduction in the content of carbohydrates and calories (up to 99%, for both) in relation to food (<82% and <85%, respectively). The results suggest that reducing sugar in solid foods remains a greater challenge than in beverages and that this reduction has less impact on the final energy density of foods.     

Sensory characteristics and relative sweetness of tagatose and other sweeteners

The present study investigated the sensory characteristics and relative sweetness of tagatose, an emerging natural low-calorie sweetener with various functional properties, compared to other sweeteners (sucrose, sucralose, erythritol, rebaudioside A), over a wide range of sweetness commonly found in foods and beverages (3% to 20% sucrose [w/v]). A total of 34 subjects evaluated aqueous solutions of the 5 sweeteners for the perceived intensities of sweetness, bitterness, astringency, chemical-like sensations, and sweet aftertaste, using the general version of the Labeled Magnitude Scale. The relationship between the physical concentrations of the sweeteners and their perceived sweetness (that is, psychophysical functions) was derived to quantify the relative sweetness and potency of the sweeteners. The results suggest that tagatose elicits a sweet taste without undesirable qualities (bitterness, astringency, chemical-like sensations). Out of the 5 sweeteners tested, rebaudioside A was the only sweetener with notable bitterness and chemical-like sensations, which became progressively intense with increasing concentration (P < 0.001). In terms of perceived sweetness intensity, the bulk sweeteners (tagatose, erythritol, sucrose) had similar sweetness growth rates (slopes > 1), whereas the high-potency sweeteners (sucralose, rebaudioside A) yielded much flatter sweetness functions (slopes < 1). Because the sweetness of tagatose and sucrose grew at near-identical rates (slope = 1.41 and 1.40, respectively), tagatose produced about the same relative sweetness to sucrose across the concentrations tested. However, the relative sweetness of other sweeteners to sucrose was highly concentration dependent. Consequently, sweetness potencies of other sweeteners varied across the concentrations tested, ranging from 0.50 to 0.78 for erythritol, 220 to 1900 for sucralose, and 300 to 440 for rebaudioside A, while tagatose was estimated to be approximately 0.90 times as potent as sucrose irrespective of concentration. Practical Application: The present study investigated the sensory characteristics and relative sweetness of tagatose, an emerging natural low-calorie sweetener, compared to other sweeteners. Study results suggest that tagatose elicits a sweet taste without undesirable qualities over a wide range of concentrations. Tagatose produced about the same relative sweetness to sucrose across the concentrations tested, while the relative sweetness of other sweeteners was highly concentration dependent. The present data provide a general guideline when considering the use of tagatose and other sweeteners in foods and beverages.     

Bioactive compounds and sensory attributes of sour cherry puree sweetened with natural sweeteners

The aim of this study was to describe a phytochemical profile, including phenolic compounds, antioxidant capacity, colour and sensory quality attributes (colour, aroma, consistency, sweetness intensity and desirability) of a sour cherry puree (SCP) supplemented with different natural sweeteners. Supplementation of SCP with the sweeteners only slightly affected polyphenol content, which was by 9% (SCP with steviol glycosides) to 26% (SCP with erythritol) lower than in pure SCP. Furthermore, the products with natural sweeteners were characterised for the lowest antioxidant activity than the SCP sample, especially in SCP with erythritol and xylitol. In addition to having high content of polyphenols and high antioxidant activity, these products were also attractive to consumers, especially when supplemented with xylitol, palm sugar or sucrose, but not with Luo Han Kuo fruit, which was found unacceptable. The results showed that most of the obtained SCPs had very promising and interesting phytochemical properties and sensory profiles.     

Rheological and sensory performance of a protein-based sweetener (MNEI), sucrose,and aspartame in yogurt

Sweeteners and flavors are generally added to yogurt to make them more palatable. However, the addition of these ingredients may affect the fermentation process of yogurt as well as its physical and sensory characteristics. Consumers prioritize yogurt products that are “natural.” A modified single-chain form of the natural sweet protein monellin extracted from the fruit of Dioscoreophyllum cumminsii, called MNEI, could be a useful alternative to artificial sweeteners. The aim of the present work was to evaluate new rapid sensory methods in combination with rheology to assess the viability of using MNEI to develop sweetened yogurts without the calories of sugar. We studied the gelation and cooling kinetics of 4 yogurt samples (unsweetened or sweetened with MNEI, aspartame, or sucrose) by using a rheometer. Furthermore, the 4 yogurts, with and without addition of a flavoring agent, were characterized from a sensory perspective using a combination of 2 rapid sensory methods, ultra flash profile and flash profile. Rheological results showed that, when added at typical usage levels, aspartame, sucrose, and MNEI did not generally affect the yogurt fermentation process or its rheological properties. Sensory results demonstrated that texture attributes of yogurts with aspartame and sucrose were strongly linked to sweetness and flavor perception, but this was not true for MNEI-sweetened yogurts. In contrast to results obtained from samples sweetened with sucrose and aspartame, MNEI protein did not sweeten the yogurt when added before fermentation. This study highlights the enhancing effect of flavor on sweetness perception, supporting previous reports that noted synergistic effects between sucrose or aspartame and flavors. Hence, future studies should be conducted to determine how sweet proteins behave in yogurt when added after fermentation.     

控制鱼糜制品中蔗糖含量的新策略

鱼糜制品因其健康和方便食用的特性而广受消费者喜爱。蔗糖常常作为冷冻保护剂和甜味剂添加到鱼糜及其制品中,以改善其低温抗冻特性和风味。然而,传统鱼糜制品的糖含量普遍偏高,这与当前追求健康的消费理念不符。如何在降低糖含量同时保证鱼糜制品的贮藏和感官特性是目前鱼糜工业生产面临的一个重大挑战。本文探讨了蔗糖在鱼糜加工贮藏中发挥的作用,分析了鱼糜制品减糖加工工艺存在的问题以及鱼糜蛋白低温下发生冷冻变性的机制。在此基础上,本文从3个方面综述了国内外降低鱼糜制品糖含量的最新研究进展:新型抗冻剂的应用、新型甜味剂的应用、物理加工技术的应用,并对减糖策略的发展方向进行了相关预测,以期为生产健康和低糖鱼糜制品加工提供理论依据。     

香气增甜的作用机制及评价方法研究进展

食品减糖比较常见的方法是使用非营养性甜味剂,但非营养性甜味剂会带来不受欢迎的苦味或金属味及安全风险。研究表明,在某些食物中加入香气物质可以增强人体对食品的甜味感知,即利用香气增甜作用达到食品减糖效果。从气味物质种类、甜味剂浓度2个方面总结了对香气增甜作用有重要影响的因素;从正鼻途径和后鼻途径的嗅觉感受机制、脑神经及味觉感受机制、心理感受机制3个方面阐述了香气增甜的作用机制,总结了分子模拟在分析甜味剂与味觉受体结合、释放过程的应用;归纳了评价香气增甜作用大小的感官分析方法,并比较描述性感官分析法、时间强度法和感觉时间支配分析法3种感官分析方法的差异性;对香气增甜作用在食品工业中的应用现状进行了汇总;对香气增甜研究方向以及分析气味增强味觉作用机制的方法提出展望,以期为香气减糖的研究提供新思路。     

3种天然甜味剂的风味、生理功能及应用研究进展

大量研究数据表明肥胖、糖尿病和心脑血管疾病的发生与日常糖分摄入过多相关密切。因此,近年来高糖饮食引发的健康风险获得了各国政府与公众的极大关注,国际消费市场对传统甜味剂蔗糖替代品的需求急剧增长。由于消费者对化学合成甜味剂的安全性一直有所顾虑,甜度高、热量低、风味佳、兼具多重功能特性的天然甜味剂成为代糖产品开发研究的热点。目前已有部分口感与蔗糖接近的天然甜味剂产品实现了工业生产并应用于食品加工,在甜味剂行业展现广阔的市场前景。本研究主要针对应用潜力巨大的3种天然甜味剂甜菊糖苷、罗汉果甜苷与D-阿洛酮糖的风味、功能及在食品中的应用进行概述,为甜菊糖苷与罗汉果甜苷的风味改良以及D-阿洛酮糖的安全性评估等工作开展提供借鉴,以期促进天然甜味剂的食品应用深入研究。     

Low‐calorie Sweeteners and Other Sugar Substitutes: A Review of the Safety Issues

Sugar‐free or reduced‐sugar foods and beverages are very popular in the United States and other countries, and the sweeteners that make them possible are among the most conspicuous ingredients in the food supply. Extensive scientific research has demonstrated the safety of the 5 low‐calorie sweeteners currently approved for use in foods in the United States–acesulfame K, aspartame, neotame, saccharin, and sucralose. A controversial animal cancer study of aspartame conducted using unusual methodology is currently being reviewed by regulatory authorities in several countries. No other issues about the safety of these 5 sweeteners remain unresolved at the present time. Three other low‐calorie sweeteners currently used in some other countries–alitame, cyclamate, and steviol glycosides–are not approved as food ingredients in the United States. Steviol glycosides may be sold as a dietary supplement, but marketing this product as a food ingredient in the United States is illegal. A variety of polyols (sugar alcohols) and other bulk sweeteners are also accepted for use in the United States. The only significant health issue pertaining to polyols, most of which are incompletely digested, is the potential for gastrointestinal discomfort with excessive use. The availability of a variety of safe sweeteners is of benefit to consumers because it enables food manufacturers to formulate a variety of good‐tasting sweet foods and beverages that are safe for the teeth and lower in calorie content than sugar‐sweetened foods.     

The influence of natural sweetener (Stevia rebaudiana Bertoni) on bioactive compounds content in chokeberry juice

The aim was to determine the differences in nutritional quality between chokeberry juices sweetened with sucrose and green stevia powder. The quality of chokeberry juices during refrigerated storage was studied. Chokeberry juices with added green stevia powder had the higher content of analyzed bioactive compounds in comparison with juice samples sweetened with sucrose; vitamin C content increased up to two times, total phenol content up to 6% and antioxidant capacity for 3%. The content of studied bioactive compounds and antioxidant capacity during storage in period of 30 and 60 days was significantly reduced with the exception of steviol glycosides which content was not significantly reduced during the storage period.

Practical applications

Chokeberry juice is a popular, widespread product of chokeberry fruit characteristic for the dark intense red color, slightly unpleasant, bitter taste and extremely rich bioactive compounds content. Because of high nutritional quality, chokeberry juice is often consumed but with the biggest barrier of characteristic astringent taste which can be diminished by addition of sweetener. Producers often combine a low‐cost sweeteners like sucrose which shows numerous negative effects on human health. A good alternative to the sucrose and artificial sweeteners are natural sweeteners extracted from the plant material like steviol glycosides. Except sweetness, stevia products like green powder shows beneficial effect on the bioactive compounds content in the juices sweetened with it. Juices sweetened with stevia shows increased content of bioactive compounds, so such product may represent quality product from category of functional food.     

Physicochemical and psychophysical characteristics of binary mixtures of bulk and intense sweeteners

Correlating psychophysical characteristics with physicochemical properties of sweeteners is of relevance to the understanding of the origin of sweetener synergy, an essential parameter for the food manufacturer. Psychophysical evaluation was carried out on bulk sweeteners (sucrose and maltitol) and intense sweeteners (aspartame, sodium cyclamate, acesulfam-K, alitame) in mixtures. The concentrations of mixtures were calculated to be equisweet to 10% sucrose and sweetness intensity was evaluated by reference to sucrose solutions using a “sip and spit” method. While a positive synergistic phenomenon is observed for sugar/sodium cyclamate and maltitol/acesulfamK mixtures, a significant suppression effect is obtained when aspartame is added to sugars. Additivity is observed for sucrose/alitame and sucrose/acesulfamK mixtures. The origin of these differences lies in the influence of the two molecules on water structure and in the nature of their hydration. From physicochemical properties (intrinsic viscosity, Huggins coefficient, apparent specific volume, hydration number, surface tension and contact angle), alitame and aspartame seem characterised by hydrophobic hydration; sodium cyclamate, as well as the bulk sweeteners, appear more compatible with water structure and possess hydrophilic hydration. ACK is differentiated from other sweeteners by a negative hydration. Synergy occurs when components with identical types of hydration are mixed. This phenomenon is accompanied by an increase in the mobility of water molecules in the proximity of bulk sweeteners (maltitol and sucrose) and a reduction of volume of the hydrated solute molecule. Inversely, suppression and additivity occur when constituents of the mixture possess different natures of hydration, as in sucrose/aspartame mixtures, and when physicochemical properties show a reduction of the mobility of water around the sweeteners. For suppression effects, an increase in volume of the hydration sphere is also observed. Interpretation of the sweetness of mixtures of sugars and artificial sweeteners, in terms of their compatibility with water structure, is of relevance at an economic level in food formulations.     

The influence of sweeteners in probiotic Petit Suisse cheese in concentrations equivalent to that of sucrose

As in the case of probiotic functional foods in recent years, demand has increased notably for light or diet foods with added sweeteners. However, little is known about the effect of different sweeteners on the microorganisms present. Thus, the objective of the current study was to establish the ideal sucrose concentration and equivalent concentrations of different sweeteners and to determine, by microbiological analyses, the influence of these compounds on the viability of the starter and probiotic cultures used in the production of strawberry-flavored Petit Suisse cheese during its shelf life. The ideal sucrose concentration was determined using the just-about-right (JAR) scale, and the equivalent concentrations of the sweeteners were subsequently determined by the magnitude estimation method. Microbiological analyses were also carried out to check the viability of the cultures during the product’s shelf life. The results showed that the compounds Neotame (NutraSweet, Chicago, IL) and stevia presented, respectively, the greatest and least sweetening power of the sweeteners tested. None of the sweeteners used in this study exerted a negative effect on the viability of the starter or probiotic cultures, and thus we were able to obtain a probiotic, functional food with reduced calorie content.     

Parents’ and Children's Acceptance of Skim Chocolate Milks Sweetened by Monk Fruit and Stevia Leaf Extracts

Chocolate milk increases milk consumption of children, but high sugar content raises health concerns. Interest in sugar reduction and parents’ preference for natural sweeteners necessitates further research on natural nonnutritive sweeteners. However, it is important to maintain consumer acceptability, especially for children, while reducing sugar in chocolate milk. The objectives of this study were to identify the sweetness intensity perception of stevia leaf (STV) and monk fruit (MK) extracts in skim chocolate milk (SCM), to evaluate STV and MK as the sole or partial sweetener source for SCM for young adults (19 to 35 y) and children (5 to 13 y), and to determine if information on natural nonnutritive sweeteners impacted parents’ acceptability of SCM. Power function and 2‐alternative forced choice studies were used to determine the iso‐sweetness of nonnutritive sweeteners to a sucrose control in SCM (51.4 g/L, SUC control). Young adults (n = 131) evaluated 9 different SCM (SUC control, STV, MK, STV:sucrose blends, or MK:sucrose blends) in a completely randomized 2‐d test. Children (n = 167) evaluated SUC control SCM and SCM with 39.7 g/L sucrose and 46 mg/L MK (MK25) or 30 mg/L STV (STV25). Parents evaluated SUC control, MK25, and STV25 in a balanced crossover design with a 40‐d wait time between primed or unprimed ballots. Chocolate milks solely sweetened by nonnutritive sweeteners were less acceptable compared with SUC control by young adults. MK25 and STV25 were acceptable by young adults and children. The presentation of chocolate milk label information had different effects on parental acceptance. Traditional parents preferred sucrose sweetened SCM, and label conscious parents preferred SCM with natural nonnutritive sweeteners.     

Sweetness Evaluation of Mixtures of Fructose with Saccharin, Aspartame or Acesulfame K

Some sensorial properties of synthetic sweeteners are limiting factors for use in low calorie soft drinks, By combining synthetic sweeteners with small fructose additions, these limitations can be overcome. Using paired comparison evaluation tests, nonlinear sweetness/concentration relations were established against sucrose, in acidified noncarbonated mineral water, for fructose, saccharin, aspartame and Acesulfame K. In binary combinations with fructose, sweetness additivity was demonstrated, for each of the three synthetic sweeteners. This is in contrast with literature reporting specific synergistic effects. By taking advantage of the high relative sweetness of fructose, low calorie soft drinks containing as little as 2–3% sugar could not be distinguished sensorially from traditional sucrose drinks.     

The effect of frequency of consumption of artificial sweeteners on sweetness liking by women

ABSTRACT:  Research into sweetness perception and preference thus far has demonstrated that sweetness preference is related not to the total sugar consumed by an individual but the amount of refined sugar ingested. Research has yet to be conducted, however, to determine whether a diet high in artificial sweeteners contributes to sweetness liking and preference with the same result as a diet high in sugar. The purpose of this research was to determine if such a relationship exists with regard to diets high in artificially sweetened beverages. Seventy-one female participants were recruited and screened for sweetener consumption in beverages. Sixty-four of these individuals were selected for sensory testing. All participants evaluated orange juice samples (ranging from 0% added sucrose to 20% added sucrose) for liking of sweetness using a 9-point hedonic scale. Based on screening survey data, participants were categorized according to sweetener consumption group (artificial sweetener consumers and natural sweetener consumers) and by overall sweetened beverage intake (low or high, regardless of sweetener type normally consumed). Sensory data were analyzed to compare sweetness liking in each of these groups. Significant differences in liking were observed, with individuals in the high sweetened beverage intake group preferring sweeter orange juice than those in the low-intake group. Categorization by sweetener type resulted in no significant differences between the groups, indicating that regardless of the type of sweetener consumed in a beverage, liking of sweetness will be influenced in the same manner.     

Low calorie bulking agents.

Obesity, a common disorder causing excess mortality due to the development of cardiovascular disease, hypertension, respiratory illness, and diabetes, is difficult to control by simple dieting techniques. Low calorie foods, which can facilitate newer weight reduction approaches such as behavior modification, often lack adequate palatability due to the absence of carbohydrate or fat. Various low calorie bulking agents that can replace the traditionally used carbohydrates and fats are discussed in terms of caloric value, utility, and regulatory status. Methods of measuring caloric utilization of bulking agents in test animals and humans are evaluated. For fat, no really satisfactory replacement is currently available, although several promising are under development. Dietary fiber sources such as microcrystalline cellulose are receiving considerable attention as flour replacements. While the polyols have many desirable attributes, as sucrose replacements, their caloric utilization values generally prevent a significant caloric reduction when they are used in foods. Several experimental sucrose replacements are described.     

Low calorie bulking agents

Obesity, a common disorder causing excess mortality due to the development of cardiovascular disease, hypertension, respiratory illness, and diabetes, is difficult to control by simple dieting techniques. Low calorie foods, which can facilitate newer weight reduction approaches such as behavior modification, often lack adequate palatability due to the absence of carbohydrate or fat. Various low calorie bulking agents that can replace the traditionally used carbohydrates and fats are discussed in terms of caloric value, utility, and regulatory status. Methods of measuring caloric utilization of bulking agents in test animals and humans are evaluated. For fat, no really satisfactory replacement is currently available, although several promising are under development. Dietary fiber sources such as microcrystalline cellulose are receiving considerable attention as flour replacements. While the polyols have many desirable attributes, as sucrose replacements, their caloric utilization values generally prevent a significant caloric reduction when they are used in foods. Several experimental sucrose replacements are described.