Use of just-about-right scales and penalty analysis to determine appropriate concentrations of stevia sweeteners for vanilla yogurt

With the mainstream emergence of natural sweeteners such as stevia, which is available in different commercial formulations, suitability for yogurt needs to be validated. The present study aimed to determine the appropriate concentration level of 3 processed stevia sweeteners/supplements in commercial plain low-fat yogurt flavored with natural vanilla. Three different levels of sucrose, aspartame, an erythritol and 95% rebaudiana A stevia sweetener, a 95% pure mix of maltodextrin and steviol glycosides, and a cold water stevia extract were used in the study. The just-about-right level for each sweetener and consumer acceptability of each naturally flavored low-fat vanilla yogurt were evaluated. Results from penalty analysis demonstrated that only 0.7% of stevia containing maltodextrin and 95% steviol glycoside was necessary, whereas higher levels (between 4.0 to 5.5%) were more appropriate for stevia containing erythritol and 95% rebaudiana A or cold water extract of stevia, respectively. The concentrations of stevia sweeteners used influenced the perceived sweetness and sourness. In general, consumers disliked the yogurt sweetened with stevia or aspartame, and neither disliked nor liked the yogurt sweetened with sucrose, which was largely driven by perceived sourness of the base yogurt. The findings underline the importance of careful selection of stevia type and concentration as well as optimizing yogurt cultures and fermentation conditions before product launch.     

Survival of Lactobacillus casei and functional characteristics of reduced sugar red beetroot yoghurt with natural sugar substitutes

In this study, probiotic gel fermentation and functional characteristics of reduced sugar yoghurt with red beetroot bioactive components and steviol glycosides from Stevia rebaudiana extracts as natural source of noncaloric sweeteners were investigated. A significant increase in Lactobacillus casei viability and fermented gel network and a decrease in syneresis were determined in yoghurt sweetened with steviol glycosides and high content of red beetroot bioactive components such as total phenolics, anthocyanins and total antioxidant capacity (DPPH and FRAP). The survival of L. casei was maintained within probiotic and therapeutic levels (>9 log₁₀ CFU/g), due to the possible prebiotic effect of steviol glycosides and fermentable fibres and phenolic compounds of red beetroot during 28 days of cold storage of the probiotic yoghurts. Colour properties (L*, a*, b*, ΔE*, C*, h*) and such sensory properties as smoothness, sweetness astringency were significantly affected. The highest organic acid content was found in red beetroot enriched yoghurt with stevia, while the most dominant organic acids were butyric, lactic, malic and citric. As a result, it was determined that fermented milk products, which are supported by phytochemical and steviol glycoside interactions, have adequate nutritional effects, high probiotic viability and acceptable sensory properties     

Application of multiple-sip temporal dominance of sensations to the evaluation of sweeteners

The dynamic sensory profile of sweeteners is of great importance for the industry during the development of low-calorie products. In the present work the influence of sucrose replacement by low-calorie sweeteners on the dynamic sensory profile of orange juice was evaluated using multiple-sip Temporal Dominance of Sensations (TDS). Seven orange juices with equivalent sweet concentrations of different sweeteners (sucrose, sucralose, thaumatin, and four samples of stevia) were formulated. A sensory panel of 12 trained assessors evaluated the samples using TDS over three consecutive sips, each lasting 20 s. TDS enabled the identification of differences in the dynamics of the sensory characteristics of the juices formulated with different sweeteners, which had not been identified using static measurements. Considering the dominance of the evaluated sensory characteristics over the three sips, the juice with sucralose showed the most similar sensory characteristics to the juice sweetened with sucrose, providing similar sweetness dominance over time without providing negative sensory characteristics. On the other hand, samples of stevia were characterized by a high dominance of bitterness and off-flavor. The consideration of multiple sips enabled the identification of changes in the temporal profile of the juices with repeated rapid ingestions. Results from the present work suggest that multiple sip TDS seems to be an interesting tool for the evaluation of sweeteners, the design of mixtures of sweeteners and the development of low-calorie products.     

Classification of stevia sweeteners in soft drinks using liquid chromatography and time-of-flight mass spectrometry

The aim of this study was to develop a comprehensive analytical method for the characterisation of stevia sweeteners in soft drinks. By using LC and time-of-flight MS, we detected 30 steviol glycosides from nine stevia sweeteners. The mass spectral data of these compounds were applied to the analysis to determine steviol glycosides in nine soft drinks. On the basis of chromatographic data and principal-component analysis, these soft drinks were classified into three groups, and the soft drinks of each group, respectively, contained high-rebaudioside A extract, normal stevia extract or alfa-glucosyltransferase–treated stevia extract.     

SWEETNESS EQUIVALENCE OF DIFFERENT SWEETENERS IN STRAWBERRY‐FLAVORED YOGURT

ABSTRACT

To successfully substitute sucrose for sweeteners, further studies must be carried out based on previous knowledge of sweetener concentration to determine the equivalent sweetness of such compounds. In this work, sweetness equivalence of strawberry‐flavored yogurt with different sweeteners and/or their combinations (aspartame, acesulfame‐K, cyclamate, saccharin, stevia and sucralose) and yogurt sweetened with 11.5% w/w sucrose was measured using the sensory magnitude estimation method. The sweetness concentrations equivalent to strawberry yogurt sweetened with 11.5% w/w sucrose in the tested sweeteners were 0.072% w/w for aspartame, 0.042% w/w for aspartame/acesulfame‐K (2:1), 0.064% w/w for cyclamate/saccharin, 0.043% w/w for cyclamate/saccharin (2:1)/stevia (1.8:1) and 0.30% w/w for sucralose. These results can promote the use of different sweetener combinations in strawberry‐flavored yogurt, specially acesulfame‐K and stevia, once they produce more pleasing in this product.

PRACTICAL APPLICATIONS

This study provides some useful information, since there is no data in the literature about sweetness equivalence of sweeteners in yogurt, but only in simpler matrices such as pure water, juices, coffee and teas. The use of stevia blend presented several advantages such as increased sweetening power, demonstrating the potential of this natural sweetener. The magnitude estimation method has been successful in this study, being an important tool for development of new low‐calorie products. It may be noted that when evaluating different types of food using the same kinds of sweeteners, these promote distinct characteristics and that reflect directly on the sensory quality of the final product. Thus, such studies generate important information for the food industries working with dietetic food.     

Combined use of cocoa dietary fibre and steviol glycosides in low‐calorie muffins production

Today, consumers are more conscious about nutrition and food products with health benefits. In this study, partial sucrose replacement (20%) with steviol glycosides derived from Stevia Rebaudiana and total replacement of cocoa powder with cocoa fibre preparation in muffins were conducted. There were three levels of dietary fibre addition – 3%, 6% and 12%. Physical analysis of texture, colour, cooking yield and porosity was conducted. Moreover, chemical analysis of total dietary fibre and total phenol content was made as well. Sensory evaluation in two parts was also carried out. The experiment revealed the increase in firmness, porosity, TDF and TCP and the decrease in springiness, cohesiveness and lightness. The best‐ranked sample in sensory evaluation was muffin with 6% of TDF sweetened with mixture of sugar and stevia. Stevia addition enhanced cocoa and sweet taste in tested muffins.     

甜菊糖苷类物质的功能性研究进展

甜菊糖苷是一类从甜叶菊叶子中提取的高甜度、低热值的甜味剂,是一种非常理想的蔗糖替代品。毒理学实验表明,甜菊糖苷不具有致畸、致癌和致突变毒性。除了作为优良的甜味剂应用在食品、饮料中,甜菊糖苷还表现出许多功能活性,如降血压、降血糖、抗肿瘤、抑菌、抗腹泻、增溶等。由于甜菊糖苷的结构可调性,可以对其进行定向修饰,得到更多具有潜在应用价值的衍生物,这方面的研究对于甜菊糖苷的深入开发利用具有重要意义,本文将围绕近几年有关甜菊糖苷功能性的研究展开讨论。     

Steviol glycosides are not altered during commercial extraction and purification processes

Steviol glycosides, sweet diterpenes extracted from the shrub Stevia rebaudiana Bertoni, are approved as sweeteners in many countries throughout the world. Former heat and pH‐investigations of these glycosides have established their stability. However, due to the complex purification process, the natural authenticity has still been discussed and challenged, recently. Thus, the objective of this work was to show that the steviol glycosides are not chemically modified during the commercial extraction and purification process. Therefore, samples of three independent commercial‐scale extraction and purification batches of steviol glycosides, each batch containing a sample of the untreated stevia leaves, the first water extract and the high‐purity end product, were analysed using HPLC‐UV and HPLC‐ESI‐MS/MS. The results show that the commercial powders of extracted steviol glycosides with an estimated purity of more than or equal to 95% contain the same steviol glycosides as the dried stevia leaves and their hot water infusions, demonstrating that steviol glycosides are not affected by the purification process.     

Comparative Analysis of the Antioxidant Capacity of Selected Fruit Juices and Nectars: Chokeberry Juice as a Rich Source of Polyphenols

The bioactive compounds, and hence the antioxidant capacity, of fruit juice are affected by a given type of juice and fruit processing conditions. In this study, some polyphenol-rich juices and nectars were compared, considering the manufacturing conditions (Stage I). Organic chokeberry juice was determined to possess the highest antioxidant capacity, which was 4- to 10-fold higher than in other popular juices. Subsequently, this juice was analyzed for selected flavonoids (flavanols, flavonols, flavones) and phenolic acids (Stage II). The results showed that chokeberry juice was a rich source of chlorogenic and neochlorogenic acids. The high total content of polyphenols and high antioxidant capacity encourage further clinical research on chokeberry juice, in the context of cardiovascular diseases prophylaxis.     

典型甜菊糖苷的抗氧化和抗炎活性

本文以6种代表性甜菊糖苷及其肠道代谢物甜菊醇以及甜菊醇的重排异构体异甜菊醇为对象,研究了上述甜菊化合物的抗氧化性及其对鼠巨噬细胞Raw264.7的细胞毒性和抗炎活性。结果表明,所试甜菊糖苷在100 μg/mL内对鼠巨噬细胞的Raw264.7均无细胞毒性,也不会诱导炎症反应;其中异甜菊醇抗炎效果最优,100 μg/mL时相对于脂多糖刺激后产生的NO含量降低了约30.7%。所试甜菊糖苷对DPPH·和·OH两种自由基的清除率最高分别为24.8%和13.8%,其对DPPH·的清除能力具有结构相关性,但对·OH清除率均低,无结构相关性;而甜菊酚对DPPH·和ABTS+·清除率分别为92.1%和29.6%,即甜菊提取物的自由基清除率主要由甜菊酚产生。     

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。     

Ultra-HPLC method for quality and adulterant assessment of steviol glycosides sweeteners – Stevia rebaudiana and stevia products

Stevia products are advertised as a zero-calorie sweetener. Glucose should not be an intrinsic component of this product, but it has been identified from some of stevia products in a preliminary study. An UHPLC-UV method was developed for the quantitative determination of glucose from stevia products. After stevia products reacted with 1-phenyl-3-methyl-5-pyrazolone (PMP), PMP derivatives were analysed and glucose was found in seven out of 35 products in the range 0.3–91.5% (w/w). Two products, SPR-12 and SPR-27, showed remarkable amounts of glucose at 61.6% and 91.5%, respectively. In addition, an UHPLC-UV-evaporative light-scattering detector (ELSD) method was developed for the quantitative determination of rebaudioside A, stevioside, rebaudioside D, dulcoside A and steviolbioside from Stevia rebaudiana and related products. In a 12 min run, five steviol glycosides were baseline-separated. ELSD and ultraviolet (UV) detections showed comparable results. The LC methods were validated for linearity, repeatability, accuracy, limits of detection (LOD) and limits of quantification (LOQ). For steviol glycosides, the LODs and LOQs were found to be less than 10 and 30 μg ml^–1, respectively. The RSD for intra- and inter-day analyses was less than 2.5%, and the recovery was 90–94%. For PMP derivative of glucose, the LOD and LOQ were 0.01 and 0.05 μg ml^–1, respectively. Repeatability (RSD) was less than 2.6%; recovery was 98.6–101.7%. The methods are useful for the identification, quality assurance, and adulterant assessment of S. rebaudiana and steviol glycosides sweeteners (stevia products).     

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.     

Physical characterization of low-calorie chocolate formulations

Development of a high-quality low-calorie chocolate needs the use of the most appropriate ingredients that could substitute sugar without negatively affecting several product properties. In this study, sucrose-reduced chocolates sweetened with sucralose and stevia by using bulking agents were investigated in relation to their rheological, textural and sensory attributes. Dark, milk and white chocolates with different amounts of sweeteners were formulated. The Casson model best fitted to the rheological data. In dark chocolates, partial substitution of sucrose with stevia (DCSSt) gave similar plastic viscosity and yield stress values with control samples (DCS). Hardness measurements also supported these results. DCSSt sample was again found to be very similar to control in tested sensory attributes when assessed by a consumer panel. The data indicated that it was possible to manufacture chocolate by partial replacement of sucrose with stevia without adversely affecting its important rheological, textural properties and sensory acceptance.     

Comprehensive review on agro technologies of low‐calorie natural sweetener stevia (Stevia rebaudiana Bertoni): a boon to diabetic patients

Stevia rebaudiana Bertoni is a low‐calorie natural sweetener plant native to Paraguay. The leaves of stevia have sweetening compounds called steviol glycosides (SGs), which contain different marker compounds, i.e. stevioside (St), rebaudioside (Rb) A, B, C, D and E, dulcoside A and steviol biosides, which are nearly 300 times sweeter than sugar. Stevia is a better alternative to sugar in formulating food products, reducing the harmful effect of sugar and improving the nutrient properties. We have tried to compile a literature on various agronomic and management aspects which are helpful in increasing the yield and quality of stevia to be grown as a crop that will benefit farmers and industrialists. The stevioside thus obtained can be used to make different food products for sweetening purposes, which could be a boon to diabetic patients. Incorporation of different agronomic techniques like propagation method, transplanting time, intercropping, irrigation, mulching, plant geometry, pinching and harvesting time not only improve the biomass but also increase the quality of stevia. Therefore, agronomic considerations are of high priority to utilize its maximum potential. © 2015 Society of Chemical Industry     

SUPERCRITICAL CARBON DIOXIDE PERCOLATION OF SEA BUCKTHORN PRESS JUICE1

Sea buckthorn press juice was subjected to percolation with supercritical carbon dioxide at 13.8 and 27.6 MPa. Control juice was not percolated. Percolation extracted about 81 % of the oil present in the press juice, lightened the orange color compared with the control juice, and changed the character of the juice as perceived by observers. Percolated juices had no visible particulate that adhered to glass surfaces as did the control juice. All juices were perceived by taste panelists as to be very sour, and it was decided to sweeten the juices with 10% sucrose before proceeding with sensory evaluations. Control juice was more yellow and thicker in consistency than the percolated juices which did not differ from each other. Juices prepared by 27.6 MPa percolation were more frequently reported as having citrus and peach‐like quality attributes compared with either of the other two juices. Analytical values for protein, oil, moisture, titratable acidity and pH were reported for the juices. Light microscopy indicated a lower oil content in the percolated juices and that the particle sizes were smaller in the percolated juices. Some morphological characteristics of the particles in both juice types are described.     

Examination of Sugars, Sugar Alcohols, and Artificial Sweeteners as Substitutes for Sucrose in Strawberry Jam. Product Development

Preparation of acceptable low sugar jams and replacement of sucrose by other sweeteners in jam were studied. Strawberry jam was sweetened with sucrose, fructose, high fructose syrup (HFS), xylitol, sorbitol, lactose, saccharin, cyclamate, or with combinations of these. It was technologically possible to prepare jams with lower amounts of sucrose than currently used and still attain an acceptable product. In addition, sucrose can be replaced in strawberry jam by other sweeteners or by combinations of sweeteners. The attainment of a suitable texture may be more difficult in xylitol and sorbitol jams than in jams with other sweeteners. The use of maltodextrin as bulking agent in jam is limited by the abnormal appearance and taste it gives to the product.     

Different sweeteners in peach nectar: Ideal and equivalent sweetness

Many articles have been published with negative visions related to sugar, because people believe that its intake is related to obesity. For this reason, artificial sweeteners have received special attention. In order to substitute sucrose successfully, it is necessary to know previously sweetener concentrations that would be used and their sweetness equivalency related to sucrose. Hence, the objectives of this study were to determine the ideal sweetness in a peach nectar sweetened with sucrose, using a just-about-right scale, and the equivalent sweetness of samples sweetened with aspartame; cyclamate/saccharin blend 2:1; stevia; sucralose and acesulfame-K, using Magnitude Estimation. The concentration of sucrose considered as ideal by the consumers was 10%, with sweeteners’ equivalent concentrations of 0.054% for aspartame; 0.036% for cyclamate/saccharin blend 2:1; 0.10% for stevia; 0.016% for sucralose and 0.053% for acesulfame-K.     

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.     

中温α-淀粉酶改性甜菊糖的研究

利用中温α-淀粉酶BAN 480L的转糖基活性,对甜菊糖分子进行改性。实验结果表明,以马铃薯淀粉和甜菊糖为底物,转糖基反应主要发生在味质需要改善的组分甜菊苷上,而味质最好的组分莱鲍迪苷A几乎不发生转糖基反应。经优化得到反应的最佳条件:甜菊糖20 g/L,马铃薯淀粉160 g/L,温度70℃,pH 6.5,酶添加量2 KNU/g淀粉,反应6 h。甜菊苷的转化率为38.9%。反应液经大孔吸附树脂分离纯化,得到了脱除淀粉糖的产品。感官评定结果表明,产品后苦味明显改善,甜度和口感均优于原料。