Chapter

Natural low-calorie sweeteners

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Abstract

Natural low-calorie sweeteners have received renewed attention with the toxicological acceptance and commercial development of steviol glycosides in the West. Excluding the simple sugars and polyols, there are 100 or more sweet compounds found in nature. However, the majority of these have little prospect of becoming commercial ingredients because they fail to meet one or more key criteria for commercial success. This chapter concentrates on the small number of natural, low-calorie sweeteners that either are, or are likely to become, commercially successful. Others that may be encountered in the literature are mentioned briefly for completeness.

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... Özellikle, thaumatin ve monellin dahil olmak üzere tatlı proteinlerin mikroorganizmalar tarafından üretilmesi denenmiştir (Masuda & Kitabatake, 2006). Örneğin, brazzein artık maya kullanılarak fermente olarak üretilmekte, taumatin ise transgenik arpadan başarıyla elde edilmiştir (Fry, 2012). Ancak çalışılan transgenik bitkilerdeki rekombinant protein birikim seviyeleri oldukça düşük bulunmuştur (Ezura & Hiwasa-tanase, 2018). ...
... Meyvede thaumatin proteinin I, II, III, a ve b olmak üzere hepsi tatlı olan beş izoformu bulunmuştur. Thaumatin I ve II ana formlardır (Fry, 2012). Bu protein, 70 °C'ye kadar ısıya dayanıklıdır ancak nötr yada alkali ortamlarda daha yüksek sıcaklıkta tatlılığını kaybetmektedir (Zeece, 2020) . ...
... İndirgeyici bir maddenin varlığında ve yokluğunda SDS-PAGE analizi, disülfüt bağları ile bağlanan yaklaşık 12 kDa'lık alt birimlerden oluştuğu gösterilmiştir (Faus, 2000;Neiers et al., 2016). Pentadin tütsülenmiş, kurutulmuş meyvelerden elde edilmiştir ve taze meyveden elde edilen brazzeinden gerçekten farklı olup olmadığı belirsizdir (Fry, 2012). ...
Conference Paper
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Fitokimyasallar, bitkiler tarafından çeşitli kimyasal yollarla üretilen besleyici olmayan kimyasal bileşiklerdir. Sağlık üzerine birçok yararlı etkileri olan fitokimyasallar polifenoller, terpenoidler, organosülfürler, fitosteroller olmak üzere dört başlık altında incelenebilir. Polifenoller kendi içinde 5 ana başlığa daha ayrılır: Basit fenolik asitler, stilbenler, kurkuminoidler, lignanlar ve flavonoidler. Terpenoidlerin arasında karotenoidler (laykopen, lutein ve karoten) ve sesquiterpenler bulunur. Organasülfür bileşikler arasında allil sülfit, allisin ve alliksin bulunur. Bu bileşikler sarımsak, soğan, pırasa gibi sebzelerde bol miktarda bulunmaktadır. Son olarak kolesterol benzeri yapıda olan ve kalp sağlığı ile ilgili önemli etkileri olduğu düşünülen fitostreroller arasında kampestrol, stigmasterol ve sitosterol bulunur. Birçok hastalığın önlenmesi veya tedavisinde etkili olan fitokimyasallar sebzelerde yoğun olarak bulunur. Genel olarak sebzeler pişirilerek tüketilmektedir. Toplumda sebzelerin çiğ olarak tüketilmesinin daha doğru olduğu kanısı olsa da pişirme ile aktif olan biyoaktif bileşikler nedeniyle pişirmenin olumlu yanları da vardır. Pişirmenin sebzeler üzerinde tek bir etkisi yoktur. Bunun sebebi sebze türlerinin farklı olması olduğu gibi pişirme süresi, sıcaklık gibi etkilerden kaynaklanıyor olabilir. Pişirme yöntemlerinden biri olan haşlama yöntemi pişirme yöntemleri arasında beslenme ve diyetetik uzmanları tarafından en çok önerilen yöntemlerden biridir. Son zamanlarda haşlama suyuna geçen vitamin ve mineraller nedeniyle haşlamanın sağlıklı olarak değerlendirilmesi sorgulanmaktadır. Bu nedenle bu çalışmada fitokimyasalları kategorize etmek ve fitokimyasalların yoğun olarak bulunduğu çeşitli sebzelerde haşlama yöntemi ile fitokimyasalların değişimini incelemek amaçlanmıştır.
... Natural sweeteners encompass wide-ranging compounds like sugars, sugar alcohols, amino acids, proteins, terpenoid glycosides and some polyphenols [84,85]. Having said that, only those that possess relevant characteristics, e.g., safety, good taste, high stability, good solubility and reasonable cost, are found on the market as widely used sweeteners [11,90]. The present review focuses on the natural sweeteners that comply with these principles. ...
... It is an ingredient frequently found in sports drinks and health bars [93]. Tagatose is a fructose isomer found naturally-occurring in certain fruit and dairy products [90]. It is considered a prebiotic and a flavour enhancer [11]. ...
... In industrial terms, it is produced from lactose following a multistep enzymatic process, plus fractionation and purification [14]. Its sweetness potency comes close to that of sucrose, 0.92, with the advantage of being differently metabolised by contributing to fewer calories, evoking a weaker glycaemic response [86,87,90] and does not favour dental caries. As it is only partly digested, tagatose can bring about diarrhoea, abdominal discomfort and flatulence when ingested as high doses [86]. ...
Article
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At a moment when the population is increasingly aware and involved in what it eats, both consumers and the food sector are showing more interest in natural foods. This review work discusses, addresses and provides details of the most important aspects of consumer’s perceptions of and attitudes to natural foods and in-depth research into natural sweeteners. It also includes issues about their use and development as regards health impacts, food security and sustainability. In line with our main research outcome, we can assume that consumers are very keen on choosing foods with clean labelling, natural ingredients, preferably with other functional properties, without the loss of taste. In response to such a phenomenon, the food industry offers consumers alternative natural sweeteners with the advantage of added health benefits. It is noteworthy that Nature is a superb source of desirable substances, and many have a sweet taste, and many still need to be studied. Finally, we must stress that being natural does not necessarily guarantee market success.
... Incubation for an hour at temperatures above 50 °C in pH 6 buffer causes a decrease in the ability to cause sweetness, and the total loss of this property occurs at 75 °C. Due to a lack of thermal stability, this protein is not suitable for use in the food industry, where high temperatures are used, because it cannot withstand the pasteurisation (Fry, 2012). ...
... Neoculin and curculin have no legal status in the EU or the USA (Fry, 2012;BarClay et al., 2014). There have been no successful attempts to obtain neoculin or curculin in transgenic plants to date (nookaraju et al., 2010). ...
Article
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The plants described in this review are a source of natural high-intensity sweeteners, which can be used in food and by the pharmaceutical industry in the future. Most of the plants are still not approved for use, even though they are traditionally used in countries where they appear naturally. Ten of the herein described intense sweeteners are characterized by a much higher sweetness in relation to sucrose. The highest values were received for miraculin, obtained from Synsepalum dulcificum (400,000 times sweeter than sucrose, induced by citric acid); thaumatin (1,600 to 3,000 times sweeter), monatin (1,200-3,000) and pentadin (500 to 2,000 times sweeter). Some of these substances can also modify the taste, like changing sour into sweet taste (miraculin and neoculin).
... The plant of Stevia rebaudiana Bertoni; which produce around 30 steviol glycosides that have sweetener role, but the best known molecules from it, are the stevioside and rebaudioside A [19][20][21][22][23][24]. The goal of this review was to do a compilation of scientific and commercial literature that provides information in regards to the concerns about the food for diabetics and the use of by products from stevia in the formulation, production and commercialization of foods for diabetic consumers. ...
... Excluding the simple sugars and polyols, there are 100 or more sweet compounds found in nature. However, the majority of these have little prospect of becoming commercial ingredients because they fail to meet one or more key criteria for commercial success [21]. ...
Article
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Diabetes has been contextualized as pandemic, but market supplying their food does not seem to grow in parallel with the problem. There are many substances on the market that will be useful as ingredients to produce foods for diabetic consumers, focusing on the sweeteners, which can be used for food processing with low calories, and low glycemic index. Natural or synthetic sweeteners have received renewed attention with the toxicological acceptance and commercial development. However, many of them have little prospect of becoming commercial ingredients because, they do not meet some of the key criteria for commercial success. The stevia plant and its products have potential for commercial uses as sweetener or therapeutic. Beside the two known main molecules that are intense sweeteners that are occurring in stevia (stevioside and rebaudioside A), the plant contain other compounds of nutritional importance for therapeutic uses. The acceptable daily intake or ADI of 4 mg/kg bw/day to steviol glycosides have been regulated to glycosides of stevia. Moreover, there exists production of stevia worldwide, with established procedures for isolation and purification of its glycosides and one of them has been approved for food use. Then, a solid market of diabetes-oriented products must emerge, for satisfying demands from these consumers.
... In particular, the total number of spray applications per season of TAG (less than 16) was in line with the commercial viticultural practices applied against powdery mildew [9] and downy mildew [7] in the environmental conditions of Northern Italy. A decreasing efcacy against downy mildew was, however, observed with an increasing amount of simulated rain, which was expected considering the high solubility of TAG in water [69]. Te low rain fastness of TAG can also explain the low efcacy on leaves and bunches under feld conditions in 2014, particularly in relation to the exceptional rain (87 mm Te application of high TAG concentration, the increase of spray application frequency during rainy periods (according to the product costs), and/or the incorporation of suitable stickers as coformulants may further improve the efcacy of this product. ...
Article
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Background and Aims. Grapevine is susceptible to several diseases and requires a large use of fungicides. Sustainable alternatives must be safe for humans and the environment and also should not interfere with must fermentation. The aim of this study was to implement the use of a rare sugar, tagatose, against powdery mildew and downy mildew and to assess possible side effects on Saccharomyces cerevisiae fermentation. Methods and Results. Tagatose was evaluated for the suppression of powdery mildew and downy mildew under controlled and field conditions and for its impact on S. cerevisiae fermentation of synthetic and grape musts. Tagatose applied at 8 kg/hareduced powdery mildew and downy mildew severity and incidence on grapevine leaves and bunches under field conditions. Tagatose caused a limited and transient slowdown of the fermentation with no negative impact on yeast viability and wine chemical composition at the end of the fermentation. Conclusions. Tagatose is a promising alternative for sustainable grapevine protection against powdery mildew and downy mildew with no negative impacts on the must fermentation. Significance of the Study. These findings pave the way for grapevine protection strategies based on the use of rare sugars as sustainable fungicides in integration with other plant protection products.
... Erythritol is a nonnutritive sugar alcohol, and is safe for human consumption (Munro et al. 1998, Fry 2012. Erythritol has insecticidal properties against SWD (Choi et al. , 2019Goffin et al. 2017;Sampson et al. 2017Sampson et al. , 2019Tang et al. 2017;Price et al. 2021a,b), deters oviposition on treated fruit (Price et al. 2021a), and can be applied as an aerosol spray on fruits. ...
Article
Drosophila suzukii Matsumura, spotted-wing drosophila, is a major pest of small fruits and cherries and often managed with conventional insecticides. Our previous work found that erythritol, a nonnutritive polyol, has insecticidal properties to D. suzukii. Two formulations of erythritol (1.5M), with 0.5M sucrose or 0.1M sucralose, are most effective at killing D. suzukii. In this study, we investigated the nontarget effects of these erythritol formulations on honey bee Apis mellifera Linnaeus larvae, a pupal parasitoid of D. suzukii, Pachycrepoideus vindemiae Rondani, and western yellow jacket, Vespula pensylvanica Saussure. We directly exposed honey bee larvae by adding a high dose (2 µl) to larval cells and found no significant mortality from either formulation compared to the water control. Pachycrepoideus vindemiae may encounter erythritol in field settings when host plants of D. suzukii are sprayed. The erythritol+sucralose formulation was more detrimental than erythritol+sucrose to P. vindemiae, however, this effect was greatly reduced within a 21-d period when a floral source was present. Since yellow jackets are a nuisance pest and were attracted to the erythritol formulations in recent field trials, we tested adult V. pensylvanica survival with continuous consumption of these formulations in the laboratory. We found no detectable detriment from either formulation, compared to the sucrose control. Overall, both erythritol formulations caused minimal nontarget effects on honey bee larvae, P. vindemiae parasitoids, and western yellow jackets.
... It is stable over a broad pH and heat Approximately 11-27% of ingested sucralose is absorbed from the gut and is excreted in the kidneys. Sucralose is safe Chattopadhyay et al. (2014) so no changes where said about behavior of electrophoresis and sweetness (the stability of brazzein is retained after at 80 °C for 4 h or 0.05% brazzein for 2 h at 98 °C in buffers at pH 2, 4, 6 and 8 (Fry 2012). It's small in size and molecular mass is 6.4 kDa and isoelectric point is 5. It's a monomer protein that consisting of 54 amino acid residues with 8 cysteines and four disulfide bonds. ...
Article
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The increasing prevalence of diseases caused by sugar consumption has become a threat to human health, and various studies have reported the relationship between high sugar consumption and the risk of various cardiovascular diseases, obesity, type 2 diabetes. Sugar-free products such as low-calorie sweeteners, especially peptide types, are very popular today due to the production of fewer calories. These sweeteners often have a protein structure and have a wide variety in terms of taste and dosage. Although extensive studies consider sweeteners to be safe and suitable substitutes for sugar, studies show that artificial types of these sweeteners can cause oxidative stress, metabolic syndrome, nervous system diseases, changes in the gastrointestinal microflora. Despite these conflicting studies, food safety organizations such as the FDA, FAO, EFSA limit the consumption of sweeteners to the acceptable daily intake (ADI) for all people, except for cases such as phenylketonuria. The purpose of this study is to briefly introduce natural peptide sweeteners (NPSs) that are good candidates to replace sugar and artificial sweeteners. The most important NPSs discussed in this summary include thaumatin, brazzein, monellin, curculin, miraculin, mabinlin, pentadin, whose safety, dosage and toxicity are discussed. Among the NPSs, thaumatin has been approved by FDA. This protein offers sweetness about 2000 times more than sucrose while produces only 4 kcal/g. NPSs generally show fewer side effects than synthetic types. The use of other NPS is also currently legal as a flavor enhancer and sugar substitute, but there are still challenges to their approval by the FDA.
... Although tagatose efficacy against tomato late blight was largely documented under greenhouse conditions [14,15], no information is available on tagatose persistence on tomato leaves. Considering the high solubility of tagatose in water [18], decreasing efficacy against phytopathogens is expected under field conditions in case of heavy rain or prolonged rainy periods [19]. Moreover, plant leaves are usually colonized by a variety of microorganisms [20][21][22], but no information is available on the possible presence of tagatose-metabolizing bacteria on tomato leaves. ...
Article
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Tagatose is a rare sugar that suppresses plant diseases, such as late blight of tomato, caused by Phytophthora infestans. Tagatose can be metabolized by some microorganisms and no information is available on its persistence on tomato leaves. The aim of this study was to assess the persistence of tagatose on tomato leaves under commercial greenhouse conditions. The amount of tagatose on tomato leaves and the inhibitory activity against P. infestans decreased seven days after spray application in the absence of rain wash-off. Potential tagatose-degrading bacteria were isolated from tomato leaves, and they belonged to Acinetobacter sp., Bacillus sp., Comamonas sp., Enterobacter sp., Methylobacterium sp., Microbacterium sp., Pantoea sp., Plantibacter sp., Pseudomonas sp., Ralstonia sp., Rhodococcus sp., Sphingobium sp., and Sphingomonas sp. Thus, indigenous phyllosphere microorganisms could partially metabolize tagatose laid on plant leaves after spray application, reducing the persistence of this fungal inhibitor on tomato leaves.
... However, studies found that the oral administration of GL is poorly absorbed from the gut, but it is slowly converted into 18β-GA under intestinal bacterial hydrolysis, and the hydrolysis product 18β-GA is absorbed in the gut [49,50]. Therefore, due to the poor bioavailability of GL, it has been designed to conjugate with various metals or ammonium to form water-soluble salts for improving its bioavailability, including ammonium glycyrrhizinate (AG), diammonium glycyrrhizinate (DG), and dipotassium glycyrrhizinate [51][52][53]. The structures of GL, GA, AG, and DG are shown in Figure 1. ...
Article
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Type 2 diabetes mellitus (T2DM) is a chronic metabolic disease, which is characterized by hyperglycemia, chronic insulin resistance, progressive decline in β-cell function, and defect in insulin secretion. It has become one of the leading causes of death worldwide. At present, there is no cure for T2DM, but it can be treated, and blood glucose levels can be controlled. It has been reported that diabetic patients may suffer from the adverse effects of conventional medicine. Therefore, alternative therapy, such as traditional Chinese medicine (TCM), can be used to manage and treat diabetes. In this review, glycyrrhizic acid (GL) and its derivatives are suggested to be promising candidates for the treatment of T2DM and its complications. It is the principal bioactive constituent in licorice, one type of TCM. This review comprehensively summarized the therapeutic effects and related mechanisms of GL and its derivatives in managing blood glucose levels and treating T2DM and its complications. In addition, it also discusses existing clinical trials and highlights the research gap in clinical research. In summary, this review can provide a further understanding of GL and its derivatives in T2DM as well as its complications and recent progress in the development of potential drugs targeting T2DM.
... When the GLY: ERY was 0:4, the water contact angle of the corn starch-based films were the largest, indicating that the hydrophilicity of corn starch-based films was the lowest. This observation could be that ERY is not hydrophilic, so it has a large contact angle when the ratio of GLY: ERY is 4:0 (40). With the increase in GLY ratio, the contact angle of corn starch-based films decreased, indicating that the hydrophilicity was enormously increased. ...
Article
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The demand for biodegradable products has increased; hence, a suitable method for producing green composites is essential. This study prepared corn starch-based films using the solution casting method, and the physicochemical properties of the prepared films were investigated using a mixture of glycerol (GLY) and erythritol (ERY) at different ratios (4:0, 3:1, 2:2, 1:3, and 0:4) as plasticizing agents. The crystallinity, hydrophilicity, mechanical properties, oxygen and water vapor, surface roughness, and thermal stability of corn starch-based films were analyzed using small-angle X-ray diffraction, water contact angle, automatic tensile testing machine, oxygen permeability tester and water vapor permeability analyzer, atomic force microscope, and thermogravimetric analyzer. With the increase in GLY ratio, the thickness, water-solubility, water content, water vapor permeability, elongation at break, oxygen permeability and V-shaped crystallization of the corn starch-based films increased. The tensile strength and the thermal stability decreased with increasing the GLY ratio. We developed a new plasticizer using glycerol and erythritol to improve the properties of starch films and provided the basis for the industrial production of corn starch-based films.
... Sweet prayer plant (Thaumatococcus danielli L.) also known as 'miracle fruit' is a wild shrub that grows widely in the rainforest of West Africa, majorly in Nigeria, Ghana and Ivory Coast. The plant can attain a height of 3-4 m with up to 46 cm long papery leaves [24], which are used for wrapping of food and making local mat in Nigeria. This study aimed at investigating the inhibitive effect of sweet prayer leaf extract on corrosion of mild steel in alkaline medium (NaOH). ...
Article
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Equilibrium and Thermodynamic Characteristics of the Corrosion Inhibition of Mild Steel Using Sweet Prayer Leaf Extract in Alkaline Medium
... Apart from the previously mentioned sweeteners, there are several sweet compounds that are found in nature belonging to three classes namely terpenoids, flavonoids, and proteins (Kinghorn and Compadre, 2001;Fry, 2012). Most proteins do not necessarily elicit any sweet taste and flavor. ...
Article
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There is currently a worldwide trend to reduce sugar consumption. This trend is mostly met by the use of artificial non-nutritive sweeteners. However, these sweeteners have also been proven to have adverse health effects such as dizziness, headaches, gastrointestinal issues, and mood changes for aspartame. One of the solutions lies in the commercialization of sweet proteins, which are not associated with adverse health effects. Of these proteins, thaumatin is one of the most studied and most promising alternatives for sugars and artificial sweeteners. Since the natural production of these proteins is often too expensive, biochemical production methods are currently under investigation. With these methods, recombinant DNA technology is used for the production of sweet proteins in a host organism. The most promising host known today is the methylotrophic yeast, Pichia pastoris. This yeast has a tightly regulated methanol-induced promotor, allowing a good control over the recombinant protein production. Great efforts have been undertaken for improving the yields and purities of thaumatin productions, but a further optimization is still desired. This review focuses on (i) the motivation for using and producing sweet proteins, (ii) the properties and history of thaumatin, (iii) the production of recombinant sweet proteins, and (iv) future possibilities for process optimization based on a systems biology approach.
... Because the intensely sweet protein (on a molar basis, some thaumatin domain containing sequences are 100,000 times sweeter than sucrose and from 300 to 3000 on the weight basis) [68], some proteins with a thaumatin domain have been explored since the 1990s by the food and pharmaceutical industry as a "natural flavor modifier or enhancer", replacing synthetic sweeteners [69,70]. However, limitations related to obtaining this protein from its natural source (fruits of T. daniellii) have hindered its use [69,71]. ...
Article
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Thaumatin-like proteins (TLPs) are a highly complex protein family associated with host defense and developmental processes in plants, animals, and fungi. They are highly diverse in angiosperms, for which they are classified as the PR-5 (Pathogenesis-Related-5) protein family. In plants, TLPs have a variety of properties associated with their structural diversity. They are mostly associated with responses to biotic stresses, in addition to some predicted activities under drought and osmotic stresses. The present review covers aspects related to the structure, evolution, gene expression, and biotechnological potential of TLPs. The efficiency of the discovery of new TLPs is below its potential, considering the availability of omics data. Furthermore, we present an exemplary bioinformatics annotation procedure that was applied to cowpea (Vigna unguiculata) transcriptome, including libraries of two tissues (root and leaf), and two stress types (biotic/abiotic) generated using different sequencing approaches. Even without using genomic sequences, the pipeline uncovered 56 TLP candidates in both tissues and stresses. Interestingly, abiotic stress (root dehydration) was associated with a high number of modulated TLP isoforms. The nomenclature used so far for TLPs was also evaluated, considering TLP structure and possible functions identified to date. It is clear that plant TLPs are promising candidates for breeding purposes and for plant transformation aiming a better performance under biotic and abiotic stresses. The development of new therapeutic drugs against human fungal pathogens also deserves attention. Despite that, applications derived from TLP molecules are still below their potential, as it is evident in our review.
... Stevioside has a slight bitter aftertaste and provides 250–300 times the sweetness of sugar.[1] The sweet diterpenoid glycoside, rebaudioside F has been isolated from leaves and its structure was established by chemical and spectral studies.[23] ...
Article
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Stevia rebaudiana regulates blood sugar, prevents hypertension and tooth decay. Other studies have shown that it has antibacterial as well as antiviral property. Preliminary phytochemical screening of aqueous, ether and methanolic extracts of S. rebaudiana was done. Acute and sub-acute toxicity were conducted on twenty four Albino rats, divided into one control (Group I) and three treatment groups viz. aqueous extract (Group II), ether extract (Group III) and methanolic extract (Group IV). For the study of antidiabetic effect of S. rebaudiana rats were divided into seven groups (n=6). Diabetes was induced by a single dose of 5% alloxan monohydrate (125 mg/kg, i.p.) after 24 hour fasting.Blood samples were analysed on day 0, 1, 5, 7, 14 and 28. Phytochemical tests showed presence of different kinds of phyto-constituents in aqueous, ether and methanol extract of Stevia rebaudiana leaves. Daily single dose (2.0 g/kg) administration of aqueous extract (A.E.) , ether extract (E.E.) and methanol extract (M.E.) for 28 days of S. rebaudiana could not show any significant change in ALT and AST levels in rats. Blood sugar level was found to be decreased on day 28 in groups of rats treated with A.E., E.E. and M.E. of S. rebaudiana. The extracts of Stevioside rebaudiana could decrease the blood glucose level in diabetic rats in time dependent manner.
Chapter
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Functional foods have been developed as a response to the demands from modern society for a heathy life style. In this way, synthetic colorants have been replaced by natural counterparts. The potential use of several natural pigments such as anthocyanins, betalains, carotenoids, annatto, β-carotene, lycopene, lutein, paprika, carminic acid, chlorophylls, and curcumin as food colorants have been explored in recent years. These pigments can be used to impart different colors in foods such as red, pink, orange, blue, green, and yellow, among others. Most of these natural colorants can be isolated from vegetal sources, with exception of lutein which can be also isolated from animal sources. However, natural pigments are sensitive to heat, oxygen, and light, as well as to modifications of pH, limiting their use as food colorants. This chapter reviews the state of the art with regard to the sources and properties of natural colorants, as well as their food applications.
Chapter
High-pressure processing, ultrasound, pulsed light, UV-light, cold plasma, and pulsed electric field are emerging nonthermal treatments for food industry application due to being cleaner, more environment-friendly, and sustainable. This processing occurs near to room temperature, and from applying the external fields – pressure or electromagnetic – several physical and chemical changes occur, resulting in desirable or undesirable food properties. This chapter describes changes caused by these techniques in natural food components/additives. Structural modifications caused by nonthermal treatments in cell membranes can increase mass transfer, improve compound extraction, and trigger defense response in plant tissues that increases phenolic compounds. Structural proteins and starch modifications are also reported. The effects promoted by nonthermal treatments in natural additives will result in increased antioxidant activity, improved digestibility, water-binding ability, and alterations of sensory, thickening, and texture characteristics. However, to obtain the benefits of nonthermal processing and avoid undesirable compound degradation, it is necessary to define the appropriate operating parameters and optimize the process. In this sense, increasing the mechanistic understanding of each treatment and its impact on the food product is necessary.
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We used data from the Campinas Health Survey (ISACamp 2014/15) and the Food Consumption and Nutritional Status Survey (ISACamp-Nutri 2015/16) to estimate the prevalence of the consumption of foods and beverages that contain low-calorie sweeteners (LCS) by individuals ≥10 years to estimate the dietary exposure of the population to high levels of LCS. We first estimated the prevalence of consuming LCS-containing foods and beverages and identified the top sources of LCS consumption. We then verified whether the prevalence of consumption varied according to individual-level characteristics or the presence of obesity and diabetes. Finally, we estimated the population dietary exposure to high levels of LCS and compared it with the acceptable daily intake (ADI) levels. Over 40% of the study population consumed at least one food or beverage containing LCS. Sweetened beverages, tabletop sweeteners and dairy beverages were the top contributors to the consumption of LCS. Among all age groups, education levels, and income levels, the consumption of foods and beverages containing LCS ranged from 35% to 55%. The prevalence was only slightly greater among higher income 40-59-year-olds than among other income groups and was not higher among individuals with obesity or diabetes. Although dietary exposure to LCS did not exceed the ADI levels, we identified several limitations in our ability to measure exposure to high levels of LCS. Because of these challenges and the unclear evidence linking LCS to better health outcomes, the consumption of foods and beverages containing LCS should be closely monitored.
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The demand for non-nutritive sweeteners of natural origin has increased in recent years, mainly driven by health concerns and the quest for a healthier lifestyle. This work aimed to investigate the content of steviol glycosides from Stevia rebaudiana Bertoni and cucurbitane glycosides from monk fruit in commercial samples of sweeteners using thermal analysis techniques (TG/DTG, DTA, and DSC), FTIR, EDS. Four commercial samples were analyzed based on steviol glycosides (E, E2, E3, E4) and one sample based on cucurbitane glycosides (M1). The thermogravimetry (TG) results showed that the thermal stability order of the samples till 200 °C was equal to E4 > M1 ≈ E2 > E > E3. Despite being marketed based on different natural glycosides, thermal analysis techniques showed similar thermal profiles between E2 and M1 samples. The DSC curves of these samples showed clear erythritol melting events, and the FTIR spectra confirmed the presence of this polyol in E2 and M1 samples. On the other hand, the DSC curve and the FTIR spectrum confirmed the presence of xylitol in the composition of the E4 sample.
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This study aimed to evaluate the impact of the addition of prebiotics and natural sweeteners on the temporal profile of mango skyr yogurts. Eight formulations were made with the addition (or not) of prebiotics (FOS) and different sweetening agents (sucrose, stevia, thaumatin, and a blend of stevia/thaumatin). The Time‐Intensity (TI) and Temporal Dominance of Sensations (TDS) analyses were performed with trained assessors (n = 12) and consumers (n = 60). The addition of prebiotics did not affect the temporal profile of the sucrose‐sweetened yogurt. Thaumatin can be used as a natural sweetener in this type of yogurt to reduce the perceived bitterness of stevia. The results revealed important data on the use of temporal methods and different panels, contributing to major understand dynamic sensory profile for concentrated yogurts sweetened with natural sweeteners, especially skyr.
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In this work, a simple method based on anthocyanins degradation by nitrite ion was used to determine cyclamate in table-top sweeteners. The method was carried out in four steps: (1) cyclamate hydrolysis (hydrolysed cyclamate, HC); (2) reaction between HC and nitrous acid; (3) anthocyanins degradation by residual nitrous acid; and (4) Absorbance measurements at 515 nm. The anthocyanins degradation reaction was done at 20 and 60 °C with 3, 5, 7, 10, and 15 mgL⁻¹ HNO2, and several reaction times were tested (15, 30, 45, 60, 90, and 120 min). Under the best conditions (60 °C, 10 mgL⁻¹HNO2 and 45 min of reaction time) the calibration curve for cyclamate was linear in the range from 3.19 to 20 mgL⁻¹; the relative standard deviation was 0.62% (for n = 5) and the limit of detection (LOD) was 0.96 mgL⁻¹. The method was applied for determination of cyclamate in table-top sweeteners and the results were compared with the official method (AOAC 957.09). The effect of synergistic sweeteners (aspartame, acesulfame, sucralose, and saccharin) was also analysed. The results show that the proposed method: (1) reduces considerably the analysis time (from 26 to 2 h, approximately); (2) decreases the LOD and the sample amount is lesser; (3) uses less number of reagents which produces few residues; and (4) it is friendly with the environment, because the anthocyanins source is a plant and the residues can be considered as non-toxics. According with the analysis of synergistic sweetener sacesulfame-K and sucralose present interference; meanwhile aspartame and saccharin (the most used with cyclamate) have not interference in the determination.
Chapter
Sugars include disaccharides such as sucrose and lactose and monosaccharides such as glucose and fructose. Sucrose is a disaccharide containing one glucose and one fructose molecule; lactose a disaccharide containing one glucose and one galactose unit. On consumption these disaccharides are broken down into the individual sugar components during digestion. This chapter outlines the reasons why consumers may wish to reduce or eliminate certain sugars from the diet as well as reviewing considerations necessary by the manufacturer when reducing or eliminating specific sugars from foods.
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Stevia-based sweeteners are beginning to enter the UK market following approval for use in the European Union in late 2011. Intensely sweet compounds, called steviol glycosides, are purified from the leaves of the stevia plant to result in a sweetener of natural origin that is about 200 times as sweet as sucrose. The scientific community has been aware of stevia for more than 100 years, yet the case for safety was not made until after reliable purity specifications were established and research results were available that closed safety gaps to the satisfaction of regulators. In food and beverage formulations, steviol glycosides exhibit characteristic behaviours and successful formulation is dependent upon understanding and managing these attributes. Steviol glycosides are particularly well suited for a variety of beverage and dairy applications, confectionery and several other foods. This is in part caused by steviol glycosides' high degree of stability in food processing. Stevia-based sweeteners offer exciting potential for use as an innovative solution for calorie and sugar reduction.
Chapter
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Sweetness intensity ratings were made by a trained panel for a range of concentrations of nineteen sweeteners. Panelists were trained to make sweetness ratings relative to six sucrose standards (2%-16%). The shapes of the concentration-response plots were sweetener-dependent. Sugars and sugar alcohols yielded linear concentration-response relationships for intensities up to that of a 16% sucrose standard. Highpotency sweeteners including aspartame, acesulfame-K and alitame yielded hyperbolic concentration-response plots.
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Noncaloric functional beverages are a key segment in the rapidly growing func- tional food market. Erythritol, an all-natural bulk sweetener, offers sensorial as well as func- tional benefits for use in such beverages. It can improve taste quality by adding body and mouthfeel, and it is capable of masking unwanted off-flavors often associated with intense sweeteners. In addition, erythritol can strengthen the functional concept since it is noncaloric, noncariogenic, and nonglycemic, and it has antioxidant properties.
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An aqaeous extract from the pulp of the plant Pentadiplandra brazzeana Baillon (Pentadiplandraceae) yielded a strong sweet-tasting material. This sweet principle was isolated by water extraction, ultrafiltration and gel filtration. The conclusion that this substance must be of a proteinaceous nature was based on amino acid analysis, characteristic UV-absorption spectrum and positive colour reaction with Coomassie brilliant blue. The mol. wt of the subunit of the sweet protein was estimated to be ˜ 12 000 daltons. The sweetness intensity of the whole protein was ˜ 500 times that of sucrose on a weight basis. The taste response in a Rhesus monkey to a 0.1 % solution was comparable to the response to a 0.02 % monellin solution. We propose the name ‘pentadin’ for this sweet-tasting protein and present a few comments about the possible origin of such sugar mimics.
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A new taste-modifying protein named curculin was extracted with 0.5 M NaCl from the fruits of Curculigo latifolia and purified by ammonium sulfate fractionation, CM-Sepharose ion-exchange chromatography, and gel filtration. Purified curculin thus obtained gave a single band having a Mr of 12,000 on sodium dodecyl sulfate-polyacrylamide gel electrophoresis in the presence of 8 M urea. The molecular weight determined by low-angle laser light scattering was 27,800. These results suggest that native curculin is a dimer of a 12,000-Da polypeptide. The complete amino acid sequence of curculin was determined by automatic Edman degradation. Curculin consists of 114 residues. Curculin itself elicits a sweet taste. After curculin, water elicits a sweet taste, and sour substances induce a stronger sense of sweetness. No protein with both sweet-tasting and taste-modifying activities has ever been found. There are five sets of tripeptides common to miraculin (a taste-modifying protein), six sets of tripeptides common to thaumatin (a sweet protein), and two sets of tripeptides common to monellin (a sweet protein). Anti-miraculin serum was not immunologically reactive with curculin. The mechanism of the taste-modifying action of curculin is discussed.
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Restriction of dietary energy extends life and reduces incidences of disease in animals. These benefits would likely extend to humans. However, diet restriction in animals imposes reductions of 30-50% in food intake, which is probably unacceptable to humans. Low-energy sweeteners used in beverages offer minor reductions in energy intake. However, they lack the bulk required for baked goods and other sugar-rich foods. Full-bulk sweeteners providing about one-half the energy of sugar are under development for such uses. Laxation limits their acceptable dose. Even within such limitations, they can help achieve the health benefits for humans indicated by diet restriction. D-Tagatose, a new candidate sweetener, is nearly as sweet as sucrose and has the bulk of sucrose, yet provides zero available energy. We discuss its potential contribution to human diet restriction along with its specific effect in delaying the aging effects of glycosylation.
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D-tagatose is a potential new sugar substitute. Ingested D-tagatose is incompletely absorbed from the small intestine; unabsorbed D-tagatose reaches the colon where it is completely fermented. In a double-blind, controlled crossover study, the gastrointestinal effects were compared following acute consumption of 40 g plain chocolates containing 20 g of sucrose, lactitol, or D-tagatose by 50 healthy adults ages 18 to 24 years. Consumption of D-tagatose was not associated with a significant increase in the frequency of passing feces, or in the number of subjects passing watery feces. However, lactitol consumption was associated with an increase in both of these occurrences. Consumption of chocolate containing D-tagatose and lactitol resulted in significant increases in colic, flatulence, borborygmi, and bloating compared to consumption of the sucrose-containing chocolate, but the majority of symptoms were described as only "slightly more than usual." D-tagatose-containing chocolate did not provoke significantly more of these symptoms than lactitol-containing chocolate. A significant number of subjects reported nausea following consumption of D-tagatose chocolate compared to the sucrose chocolate control, and multiple symptoms occurred in some subjects. Overall, these results demonstrate that a 20-g dose of D-tagatose is tolerated well in comparison to lactitol.
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Brazzein is a 54-amino-acid sweet-tasting protein first isolated from the fruit of Pentadiplandra brazzeana Baillon found in West Africa. Brazzein, as isolated from the fruit, is 500 times sweeter than sucrose on a weight basis (9500 times sweeter on a per-molecule basis). A minor component of brazzein from fruit, des-pGlu1-brazzein, has 53 amino acid residues and has twice the sweetness of the parent protein. We have designed a gene for des-pGlu1- brazzein that incorporates codons that are optimal for protein production in Escherichia coli. Production of brazzein from the chemically synthesized gene resulted in recombinant protein with sweetness similar to that of brazzein isolated from the original source. The best yields were achieved by producing brazzein as a fusion with staphylococcal nuclease with a designed cyanogen bromide cleavage site. Because of its intense sweetness and stability at high pH and temperature, brazzein is an ideal system for investigating the chemical and structural requirements involved in sweet-taste properties. This efficient protein production system for brazzein will facilitate such investigations.
Chapter
Erythritol is a unique member of the polyol family. Polyols or polyhydric alcohols are polyhydroxyl compounds typically produced through the hydrogenation of their parent reducing sugars. These compounds do not have an aldehyde group, therefore, they do not undergo a Maillard reaction and are relatively stable to heat and changes in pH. Erythritol is a small linear sugar alcohol with four carbon atoms (Figure 15.1). It belongs to the acyclic alcohols, a group of sugar alcohols. Its small molecular size gives erythritol its extraordinary physicochemical, nutritional, and physiological properties, such as a zero calorie value and good digestive tolerance that is higher compared with all other polyols. These properties will be discussed in more detail later in this chapter. Erythritol is a naturally occurring substance and the only polyol commercially produced through a natural fermentation process. It is found in a variety of foods such as grapes, pears, melons, mushrooms and in fermented products such as soy sauce, sake, and wines (Table 15.1). The concentration oferythritol in foods and fermented products can range from just a few milligram up to 1500 mg per liter or kilogram (Perko and de Cock 2006). Erythritol is a minor component ofblood and amniotic fluids of cows and other mammals (Roberts et al. 1976). It can also be found in the human body, for instance, in the lens tissue (Tomana et al. 1984), in cerebrospinal fluid (Servo et al. 1977), in seminal plasma (Storset et al. 1978), and in blood serum (Budavari 1996). Erythritol is the main polyol in the human urine with a concentration ranging from 10-30 mg/L (Goossens and Gonze 1996). Mi!da E. Embuscado and Sakharam K. Pati! did not participate in the revision but their chapter in the book's 3rd edition was the basis of this revised chapter.
Article
The majority of sweet compounds are of low-molecular- weight, but several proteins elicit sweet taste responses in humans. The fruit of Curculigo latifolia has been known to contain a protein that has both sweetness and a taste-modifying activity to convert sourness to sweetness. Recently, we have purified and re-identified the active component to reveal that it is a heterodimeric protein named "neoculin". The result of X- ray crystallographic analysis has indicated that the overall structure of neoculin is similar to those of monocot mannose- binding lectins, while there is little structural similarity between neoculin and structure-solved sweet proteins. Direct interaction between neoculin and human sweet taste receptor hT1R2-hT1R3 has been indicated by response of HEK293T cells expressing this receptor, and by the inhibition of neoculin activity with lactisole, a hT1R2-hT1R3 blocker. Combining the results of molecular dynamics simulations and docking model generation between neoculin and hT1R2-hT1R3, we propose a hypothesis that neoculin is in dynamic equilibrium between "open" and "closed" states, and that the addition of an acid shifts the equilibrium to the "open" state for easier fitting to the receptor.
Article
Interest has never been greater in the development of new sweetness technologies which enable more cost-effective food and beverage product formulation, more sugar-like taste quality and reduction in caloric levels. Guidance, targeted to organizations considering development of new sweetness technologies, is given as to the specific requirements for successful commercialization of new sweeteners and sweetness modulators. And the argument is made that a successful new sweetness technology must deliver on nine metrics, including 1) high maximal sweetness response, 2) clean flavor profile, 3) sugar-like temporal profile, 4) sugar- like sweetness adaptation profile, 5) safety, 6) stability, 7) solubility, 8) cost-effectiveness and 9) patentability. Importantly, the argument is also made that a viable new sweetness technology must deliver on all nine of these metrics in order to realize commercial success.
Article
From fruits of Siraitia grosvenori, a Chinese medicinal plant, a new minor glycoside and four known minor cucurbitane glycosides, siamenoside I (sweet), 11-oxo-mogroside V (sweet), and mogrosides IIE and IIIE (both tasteless) were isolated together with mogrosides IV and V (both sweet) previously isolated from this fruit by Arihara et al. Structure of the new testeless glycoside called mogroside III was elucidated as 3-O-β-D-glucopyranosyl- 24-O-β-gentiobiosyl-mogrol. The relative sweetness of siamenoside I to sucrose was estimated ×563, making this the sweetest compound among the cucurbitane-glycosides so far isolated. The structure-taste relationship of cucurbitane-glycosides is also described.
Article
Mogroside V (MV), a main sweet triterpene glycoside in the extract of the fruit of Luo-han-guo (Siraitia grosvenori Swingle), was transglycosylated by cyclodextrin glucanotransferases (CGTases) using starch as a donor substrate. CGTases from Bacillus macerans, B. circulans, B. stearothermophilus and Thermoanaerobacter sp. were effective for the transglycosylation of MV. It was appropriate for the production of glycosylated MV to react 9% (w/v) MV with 20% (w/v) tapioca starch and B. macerans enzyme (30 U/g-starch) at 50°C and pH 6.5. Under these conditions, the reaction finished within 24 h and more than 90% of a glycosylation yield was attained. Three products that have 1-3 additional glucose residues were identified as transglycosylation products by mass spectrometry. The greater number of glucose residues introduced, the less intensity of sweetness compared to MV was estimated by sensory evaluation. However the qualities of sweetness such as bitterness, after-taste, and peculiarity were improved by transglycosylation.
Article
The liquorice plant (Glycyrrhiza glabra L., formerly Liquiritae officinalis Moench) has been used by physicians and herbalists since the earliest of times. Many of the early claims for the effectiveness of liquorice extracts, decoctions and potions have been shown by modern science to be credible, a root component (glycyrrhizin) being generally regarded as the major biologically-active principle. Liquorice extracts (in pharmacy called succus liquiritae) are currently used mainly in the tobacco, pharmaceutical and confectionery industries; because such extracts contain glycyrrhizin there is a need for accurate methods for its estimation, in both crude isolates and finished products. The purpose of this review is to briefly describe the background to current interests in liquorice, to indicate the origins and usage of liquorice extracts and to discuss the composition of liquorice, with particular emphasis on glycyrrhizin. Current methods for the analysis of glycyrrhizin will be considered and the levels found in liquorice roots, extracts and a range of products indicated. Brief mention will also be made of human exposure levels and the possible risk to human health as a result of consuming liquorice-based products.
Article
Brazzein is a small, heat-stable, intensely sweet protein consisting of 54 amino acid residues. Based on the wild-type brazzein, 25 brazzein mutants have been produced to identify critical regions important for sweetness. To assess their sweetness, psychophysical experiments were carried out with 14 human subjects. First, the results suggest that residues 29–33 and 39–43, plus residue 36 between these stretches, as well as the C-terminus are involved in the sweetness of brazzein. Second, charge plays an important role in the interaction between brazzein and the sweet taste receptor.
Article
The structure of monatin, a high-intensity sweetener isolated from Schlerochiton ilicifolius was elucidated by 1H and 13C NMR spectroscopy as 4-hydroxy-4-(indol-3-ylmethyl)glutamic acid. The 2R*,4R* relative configuration of the two chiral centres in monatin was determined by NOE studies on a derivative, methyl 2-(indol-3-ylmethyl)-4-(2,4-dinitroanilino)-5-oxo-2,3,4,5-tetrahydrofuran-2-carboxylate. The assignment of the 2S configuration to monatin, through application of the Clough–Lutz–Jirgenson rule, established the 2S,4S configuration for the compound.
Article
Tagatose is a minimally absorbed monosaccharide that has prebiotic properties. For this prebiotic effect to be achieved, tagatose should remain stable and not degrade during food processing and storage. This study evaluated the storage stability of tagatose in solutions as affected by buffer type, buffer concentration, pH, and temperature. Tagatose does degrade during storage. Minimal tagatose loss and browning were observed in 0.02M phosphate and citrate buffers at pH 3. In 0.1M buffers at pH 3 and 40°C, approximately 5% tagatose was lost over 6months and slight browning occurred. Tagatose degradation was enhanced at pH 7, especially in phosphate buffer, where it occurred faster than in citrate buffer. Higher buffer concentrations also enhanced tagatose loss. In phosphate buffers at pH 7, browning accompanied the tagatose degradation, increasing to a maximum and then decreasing. To deliver the prebiotic effect from tagatose, shelf-stable beverages should be formulated to the lowest buffer concentration and pH possible to optimize tagatose’s stability.
Article
An efficient method was developed for the synthesis of the ketoamino acid 2, a key intermediate in the synthesis of the novel sweet compound, monatin 1. Preparation of 2 entails coupling of a suitably protected indole acetate anion to an aspartic acid derivative.
Article
The reaction of methyl 2-(3-indolylmethyl)-acrylate 2 with carbethoxyformonitrile oxide 3, followed by saponification and reduction, gives mainly racemic monatin 1. Preliminary attempts to adapt the 2+3 cycloaddition to a new chiral synthesis of monatin, is described.
Article
Monatin, a natural sweetener, refers to a collection of four isomers of 2-((1H-indol-3-yl)methyl)-4-amino-2-hydroxypentanedioic acid. A chemo-biocatalytic approach to kilogram quantities of enantiopure 2S,4S-monatin and 2R,4R-monatin from indole is described. Key steps in the process include a (2 + 3) cycloaddition reaction followed by nickel-catalysed reduction to construct the monatin backbone, and a highly selective enzyme resolution of the 2S,4S- and 2R,4R-monatin diastereomeric pair to afford each enantiomer in 99% ee.
Article
Stability of pure stevioside and rebaudioside A in carbonated phosphoric and citric acidified beverages during long-term storage was observed chemically, microbiologically, and organoleptically. Thin-layer chromatography and high-pressure liquid chromatography were used to follow the chemical degradation of these Stevia sweeteners. Some degradation of both sweeteners was observed after 2 months of storage at 37 °C; however, there were no significant changes at room temperature or below following 5 months of storage of stevioside, or 3 months of storage of rebaudioside A. Exposure to 1 week of sunlight did not affect stevioside but resulted in approximately 20% loss of rebaudioside A. Heating at 60 °C for 6 days resulted in 0-6% loss of the sweeteners.
Article
The sweet protein brazzein isolated from the fruit of the African plant, Pentadiplandra brazzeana Baillon is 2000-500 times sweeter than sucrose, and consists of 54 amino acid residues with four intramolecular disulfide bonds. Brazzein was prepared by the fluoren-9-yl-methoxycarbonyl solid-phase method, and was identical to natural brazzein by high performance liquid chromatography, mass spectroscopy, peptide mapping, and taste evaluation. The D enantiomer of brazzein was also synthesized, and was shown to be the mirror image of brazzein. The D enantiomer (ent-brazzein) was devoid of any sweetness and was essentially tasteless. © 1996 John Wiley & Sons, Inc.
Article
The authors studied the effects of temperature on the stability of thaumatin in aqueous diluted solutions at 50, 70 and 90°C. The thermodegradation follows first-order kinetics and is pH-dependent. At 20°C and pH 2, the time (t90%) necessary to obtain a decrease of 10% of the initial concentration estimated by extrapolation is 43 days for thaumatin at a concentration of 1.90 × 10–5 M. Thaumatin is most stable at pH 2.
Article
The primary structure of the sweet-tasting protein thaumatin has been elucidated. The protein consists of a single polypeptide chain of 207 residues. The sequence of the N-terminal part of the chain was determined by sequenator analysis. As the protein contains only one methionine residue, it was possible to deduce the N-terminal sequence of the C-terminal cyanogen bromide fragment by automatic sequencing of the cyanogens-bromide-cleaved, succinylated protein. To arrive at the sequence of the whole protein tryptic and Staphylococcus protease peptides, together with chymotryptic peptides and a 2-(2-nitrophenylsulfenyl)-3-methyl-3′-bromoindolenine (BNPS-skatole) fragment were also sequenced.Comparing the amino acid sequence of thaumatin with that of the other sweet-tasting protein, monellin, we have located five sets of identical tripeptides. Since immunological cross-reactivity of thaumatin antibodies with monellin has recently been described, one or more of these tripeptides might be part of a common antibody recombination site and possibly be involved in the interaction with the sweet-taste receptor.
Article
The search for non-carbohydrate sweeteners from natural sources has led to the discovery of many intensely sweet-tasting substances. The occurrence of sweet-tasting proteins such as thaumatin, monellin, mabinlin and pentadin in the pulp of fruits of various rain forest species has provided a new approach to the potential treatment of diabetes, obesity and other metabolic disorders. These proteins can also be used as low calorie sweeteners to enhance and modify the taste of existing foods. Thaumatin is currently commercially available as a sweetener, flavor enhancer, additive to pharmaceuticals, chewing gum and animal feeds. It can also be secreted extracellularly by genetic modification of the yeast Saccharomyces cerevisiae. The taste-modifying proteins, miraculin and curculin, can be utilized in controlling the palatability of foods or in the development of new food products. This review discusses some properties of sweet and taste-modifying proteins discovered to date.
Article
A general mathematical model for the temporal intensity response to a transient sweet stimulus was developed. The model is a set of nonlinear ordinary differential equations, expressing the rates of diffusion across a saliva boundary layer and adsorption and desorption to receptor site proteins on the taste bud cells. In this model, the perceived intensity is considered to be the product of a scaling factor and the amount of stimulus bound to receptor sites at any given time. A parameter estimation routine was used to fit the differential equations to the time–intensity (TI) curves for five equisweet stimuli (sucrose, aspartame, thaumatin, monellin, and brazzein). Model parameters were computed for each of 19 trained judges. The predicted TI curves were close to the observed time-intensity responses for all judges and sweeteners. TI parameters varied significantly across both judges and compounds, while model predicted parameters, such as adsorption and desorption coefficients, varied significantly only across compounds. Except for one model parameter (predicted plateau time), there were no significant differences across judges for the model-predicted parameters, indicating that all judges responded similarly to each compound.
Article
Neoculin is a sweet protein with a taste-modifying activity of converting sourness to sweetness. It occurs in the fruits of Curculigo latifolia, a wild plant found in tropical Asia. We successfully cultivated the plant and evaluated the production of neoculin. The neoculin content of the fruit was high for 10 weeks after flowering, following which the yield decreased gradually. The optimal period for harvesting the fruits with sensory activity coincided with this 10-week peak period during which the amount of neoculin was 1–3 mg in the whole fruit and 1.3 mg/g of pulp. Immunohistochemical staining showed that neoculin occurred in the whole fruit, especially at the basal portion. Although it is known that neoculin comprises an acidic subunit (NAS) with an N-glycosylated moiety and a basic subunit (NBS), protein gel blot analysis revealed the presence of a non-glycosylated NAS species. This suggests the presence of multiple NAS–NBS heterodimers in our cultivar.
Article
Rebiana is the common name for high-purity rebaudioside A, a natural non-calorie sweetener 200-300 times more potent than sucrose. It provides zero calories and has a clean, sweet taste with no significant undesirable taste characteristics. It is functional in a wide array of beverages and foods and can be blended with other non-calorie or carbohydrate sweeteners. It is stable under dry conditions, and has much better stability than aspartame or neotame in aqueous food systems. Studies undertaken for the development of a purification process and for the full characterization of the properties of rebiana are reported here.
Article
Thaumatin, a sweet protein that contains no cysteine residues and eight intramolecular disulfide bonds, aggregates upon heating at pH 7.0 above 70 degrees C, and its sweetness thereby disappears. The aggregate can be solubilized by heating in the presence of both thiol reducing reagent and SDS. This molecular aggregation depended on the protein concentration during heating and was suppressed by the addition of N-ethylmaleimide or iodoacetamide, indicating a thiol-catalyzed disulfide interchange reaction between heat-denatured molecules. An amino acid analysis of the aggregates suggested that the cysteine and lysine residues were reduced, and the formation of a cysteine residue and a lysinoalanine residue was confirmed. The reduction and formation of these residues stoichiometrically satisfied the beta-elimination of a cystine residue. The disulfide interchange reaction was catalyzed by cysteine; that is, a free sulfhydryl residue was formed via beta-elimination of a disulfide bond. Intermolecular disulfide bonds were probably formed between thaumatin molecules upon heating at pH 7.0, which led to the aggregation of thaumatin molecules.
Article
While examining the taste of various proteins, we found that hen egg-white lysozyme, a bacteriolytic enzyme, had sweetness. Lysozymes from other sources such as turkey and soft-shelled turtle also showed sweetness with different tastes, heavy or light. In contrast, human lysozyme was tasteless. The amino acid sequences of the various lysozymes were similar to that of hen lysozyme, but hen lysozyme did not show significant homology to sweet proteins.
Article
The Coca-Cola Company and Cargill, Inc. have initiated the development and commercialization of the Stevia rebaudiana (Bertoni) derived sweetener rebaudioside A. Efforts were focused on high purity rebaudioside A (>97% by HPLC), commonly known as rebiana. In the course of the development program, extensive stability studies were carried out on rebiana, all supporting good stability for use in all food and beverage applications, including conditions where rebiana-sweetened beverages were exposed to light. Our findings on rebiana light stability refute those of an earlier study that suggested rebaudioside A to be unstable to sunlight exposure, while the structurally homologous stevioside is stable. We replicated the earlier study and found no significant photodegradation for either rebaudioside A or stevioside.
Article
The crystal structure of thaumatin I, a potently sweet protein isolated from the fruits of the West African shrub, Thaumatococcus danielli Benth, has been refined at a resolution better than 1.65 A using a combination of energy minimization and stereochemically restrained least-squares methods. The final model consists of all 207 amino acids, 28 alternate amino acid conformers and 236 waters, with a crystallographic R-factor of 0.145 for 19,877 reflections having F > 4 sigma F between 10.0 A and 1.65 A (R = 0.167 for all 24,022 reflections). The model has good stereochemistry, with root-mean-square deviations from ideal values for bond and angle distances of 0.014 A and 0.029 A, respectively. The estimated root-mean-square co-ordinate error is 0.15 A. The current model confirms the previously reported 3.1 A C alpha trace in both main chain connectivity and disulfide topology, including two disulfide bonds, that differed from the earlier reported biochemical determination. The structure contains three domains. The core of the molecule consists of an eleven-stranded, flattened beta-sandwich folded into two Greek key motifs. All beta-strands in this sandwich are antiparallel except the parallel N-terminal and the C-terminal strands. The average hydrogen bond length in this sandwich is 2.89 A, with an angle of 155.1 degrees. Two beta-bulges are found in one of the sheets. The second domain consists of two beta-strands forming a beta-ribbon and connected by an omega-loop, and contains a proline residue in cis conformation. This structural motif folds back against the main sandwich to form a smaller sandwich-like structure. The third domain is a disulfide-rich region stretching away from the sandwich portion of the molecule. It contains one alpha-helix and three short helical fragments. Two of the helical segments are connected by an unusually sharp turn, stabilized by a disulfide bridge. One of the three disulfide bonds in this domain takes on two conformations.
Article
Thaumatin and monellin are the two sweetest compounds known to man--about 100,000 times sweeter than sugar on a molar basis and 3000 times on a weight basis. These proteins represent a unique class of proteins that are taste-active. We report the three-dimensional structure of thaumatin I at 3.1 A resolution.
Article
From an aqueous extract of the fruit of the tropical plant Thaumatococcus daniellii Benth, two sweet-tasting basic proteins, here named thaumatin I and thaumatin II, were isolated by ultrafiltration, gel nitration on Sephadex G-50 and ion-exchange chromatography on SE-Sephadex C-25, using a sodium chloride concentration gradient. The proteinaceous character of the two sweet-tasting compounds was proven by the characteristic ultraviolet absorption spectrum, the presence of almost 100% polypeptide material as determined by the biuret method, the yield of 100% amino acids on hydrolysis with hydrochlorid acid, the positive reaction with amido black colouring agent (as used in the analysis of the fractions by polyacrylamide gel and starch gel electrophoresis) and by the disappearance of the sweet taste of the compounds after incubation with trypsin. The basic character of the two proteins appears from their isoelectric points of almost 12, as estimated by starch gel electrophoresis at different pH values, and from the precipitation of the proteins at pH 12. The molecules of thaumatin I and II are very similar as shown from their amino acid compositions, which are practically equal; they also have the same N-terminal amino acid alanine and molecular weights of 21000 ± 600 and 20400 ± 600, respectively (calculated from ultracentrifugal data). The proteins lose their sweetness on heating, on splitting of the disulphide bridges in the molecule and at pH values below 2.5. Thaumatin I and II have an intensely sweet taste, the degree of sweetness being about 1600 times higher than that of sucrose on a Weight basis or 105 times on a molar basis. The threshold values are near 10−4% or 48 nM.
Article
The purpose of the present study was to determine the presence and degree of synergism among all binary mixtures of 14 sweeteners varying in chemical structure. A trained panel evaluated binary combinations of the following sweeteners: three sugars (fructose, glucose, sucrose), two polyhydric alcohols (mannitol, sorbitol), two diterpenoid glycosides (rebaudioside-A, stevioside), two dipeptide derivatives (alitame, aspartame), one sulfamate (sodium cyclamate), one protein (thaumatin), two N-sulfonyl amides (acesulfame-K, sodium saccharin), and one dihydrochalcone (neohesperidin dihydrochalcone). Each sweetener was tested at three concentrations that were isosweet with 3%, 5%, and 7% sucrose. Two methods of analysis were performed to determine synergistic effects. In Method I, an ANOVA was performed for each intensity level to determine if the mean sweetness intensity ratings of each binary mixture were equal to nominal sweetness (i.e., additivity) or not equal to nominal sweetness (i.e., synergism or suppression). In Method II, an additional ANOVA was performed to determine if the sweetness intensity ratings of any given mixture were equal to or greater than the average of the sweetness ratings of the two pure components in that blend.
Article
Curculin elicited a sweet taste. After the sweetness of curculin diminished, application of deionized water or an acid to the tongue induced a sweet taste. The maximum sweetness of curculin itself was equivalent to the sweetness of 0.35 M sucrose. The maximum sweetness induced by 0.02 M citric acid or deionized water after curculin dissolved in a buffer of pH 6.0 was held in mouth for 3 min was also equivalent to that of 0.35 M sucrose. The sweetness induced by deionized water was completely suppressed by the presence of 1 mM CaCl2 or MgCl2, while that induced by an acid was not suppressed by the presence of divalent cations. Based on these results, the mechanism of the taste-modifying activity was discussed. Stability of curculin was examined under various conditions. The taste-modifying activity of curculin was unchanged when curculin was incubated at 50 degrees C for 1 h between pH 3 and 11.
Article
We have discovered a new high-potency thermostable sweet protein, which we name brazzein, in a wild African plant Pentadiplandra brazzeana Baillon. Brazzein is 2,000 times sweeter than sucrose in comparison to 2% sucrose aqueous solution and 500 times in comparison to 10% of the sugar. Its taste is more similar to sucrose than that of thaumatin. Its sweetness is not destroyed by 80 degrees C for 4 h. Brazzein is comprised of 54 amino acid residues, corresponding to a molecular mass of 6,473 Da.
Article
There are several analogues of the sweet protein mabinlin. In previous studies, we purified the heat-stable analogue, mabinlin II, from the seeds of Capparis masaikai Lévl. and determined its amino acid sequence [Liu, X., Maeda, S., Hu, Z., Aiuchi, T., Nakaya, K. & Kurihara, Y. (1993) Eur. J. Biochem. 211, 281-287] and the disulfide structure [Nirasawa, S., Liu, X., Nishino, T. & Kurihara, Y. (1993) Biochim. Biophys. Acta 1202, 277-280]. We have now purified four additional homologues of mabinlin. The sweet activities of mabinlin III and mabinlin IV were unchanged by incubation for 1 h at 80 degrees C, as was found previously for mabinlin II, while the sweet activity of mabinlin I-1 was completely abolished by a 1-h incubation at 80 degrees C. The circular dichroic spectrum showed that alpha-helical structures of mabinlins II-IV were unchanged by the 1-h incubation at 80 degrees C, while the alpha-helical structures of mabinlin I-1 were completely destroyed by the 1-h incubation in parallel with the decrease of the sweet activity. To compare the structures of the heat-stable and unstable homologues, we determined their amino acid sequences and the disulfide array. The positions of four disulfide bridges of mabinlin I-1 were the same as those of mabinlin II, suggesting that the disulfide bridges do not contribute to the difference in the heat stability among the homologues. There was a high similarity among amino acid sequences of the homologoues. Only three amino acid residues (A-chain residues at positions 22 and 32 and B-chain residue at position 47) were different between mabinlin I-1 and mabinlin III. A-chain residue at position 32 was lacking in mabinlin IV and the A-chain residue at position 22 was identical in both mabinlin I-1 and mabinlin II. The B-chain residue at position 47 was the only residue present in all three heat-stable homologues (mabinlins II-IV) and is not present in the unstable homologue (mabinlin I-1). This suggests that the difference in the heat stability of mabinlin is due to the difference in a B-chain residue at position 47; the difference in the heat-stable homologues is due to the presence of an arginine residue and the difference of the unstable homologue is due to the presence of glutamine.(ABSTRACT TRUNCATED AT 400 WORDS)
Article
A new sweet protein, named mabinlin II, was extracted with 0.5 M NaCl solution from the seeds of Capparis masaikai Lévl. and purified by ammonium sulfate fractionation, carboxymethylcellulose-Sepharose ion-exchange chromatography and gel filtration. The sweetness of mabinlin II was unchanged by at least 48 h incubation at nearly boiling temperature. Purified mabinlin II thus obtained gave a single band having a molecular mass of 14 kDa on SDS/PAGE. In the presence of dithiothreitol, mabinlin II gave two bands having molecular masses of 4.6 kDa and 5.2 kDa on SDS/PAGE. Two peptides (A chain and B chain) were separated from reduced and S-carboxamidomethylated mabinlin II by HPLC. The amino acid sequences of the A chain and B chain were determined by the automatic Edman-degradation method. The A chain and B chain consist of 33-amino-acid and 72-amino-acid residues, respectively. The A chain is mostly composed of hydrophilic amino acid residues and the B chain also contains many hydrophilic residues. High similarity was found between the amino acid sequences of mabinlin II and 2S seed storage proteins, especially 2S albumin AT2S3 in Arabidopsis thaliana (mouse-ear cress).
Article
The state of the art regarding the six known sweet-tasting proteins (thaumatin, monellin, mabinlin, pentadin, brazzein and curculin) and the taste-modifying protein miraculin is reviewed. Their biochemical properties, molecular genetics and biotechnological production are assessed. All of these proteins have been isolated from plants that grow in tropical rainforests. They share no sequence homology or structural similarities. Nonetheless, one of them, thaumatin, shares extensive homology with certain non-sweet proteins found in other plants. The potential industrial applications of the sweet-tasting proteins are also discussed, placing special emphasis on the barriers that a recombinant product of these characteristics will have to overcome before it reaches the market.
Article
Hen egg lysozyme elicits a sweet taste sensation for human beings. Effects of reduction of disulfide bonds, heat treatment, and chemical modification of hen egg lysozyme on both sweetness and hydrolytic activity were investigated. Both the sweetness and enzymatic activities were lost when the intradisulfide linkage in a lysozyme molecule was reduced and S-3-(trimethylated amino) propylated. The sweetness and enzymatic activity of lysozyme were lost on heating at 95 degrees C for 18 h. These facts suggest that tertiary structures of lysozyme are indispensable for eliciting a sweet taste as well as enzymatic activity. Although the modification of carboxyl residues in a lysozyme by glycine methylester or aminomethansulfonic acid resulted in the loss of enzymatic activity by blocking the catalytic residues, the sweetness was fully retained. These results indicate that the sweetness of lysozyme was independent of its enzymatic activity. The lysozyme purified from goose egg white similarly elicited a sweet taste, although goose (g-type) lysozyme is quite different from hen egg lysozyme (c-type) on the basis of structural, immunological, and enzymatic properties. These findings indicate that a specific protein property of lysozyme is required for sweetness elicitation and that the enzymatic activity and carbohydrates produced by enzymatic reaction are not related to the sweet taste.
Article
Brazzein is a small, heat-stable, intensely sweet protein consisting of 54 amino acid residues. Based on the wild-type brazzein, 25 brazzein mutants have been produced to identify critical regions important for sweetness. To assess their sweetness, psychophysical experiments were carried out with 14 human subjects. First, the results suggest that residues 29-33 and 39-43, plus residue 36 between these stretches, as well as the C-terminus are involved in the sweetness of brazzein. Second, charge plays an important role in the interaction between brazzein and the sweet taste receptor.