The Interrelationship between Agricultural Food Crops for the Production of Sweeteners

Historically, sugar cane and sugar beets were the two major food crops that have furnished extractable sucrose as a basic sweetener need of millions throughout the world. With the revolutionary advances in enzyme technology witnessed since 1967 on corn starch, a new sweetener development is emerging that has a potential to furnish the multitudes with a natural sweetener which for all practical purposes is equivalent to the product obtained upon hydrolysis of sucrose, namely, invert. This enzymatic innovation for the conversion of corn syrup to high fructose corn syrup, is closing the gap between sweeteners from beets and cane and a high fructose syrup or an invert produced not only from corn syrup, but from any agricultural food crop rich in starch such as wheat, rice, potato or tapioca. Sucrose, invert and high fructose syrup now converge to meet the demand in furnishing energy and sweetness to the millions throughout the world.     

New Directions for Starch and Glucose Research

Enzymes have become a prime commercial tool for modification of starch and glucose. Today we see enzymes used to convert starch to glucose and again to convert glucose to a mixture of glucose and fructose, invert sugar in the terminology of cane and beet sugar manufacturers. We will expect to see greater use of enzymes to modify starch granules to produce a new way of dextrinization of starch. Enzymes may also be used to modify starch molecules to increase the degree of branching producing new properties among which can be those giving solutions of low viscosity, but high solids contents. Starch or glucose derivatives can also be sources of sugar for derivatizing protein to produce glycoproteins a potential new class of water soluble gums or food additives. Low caloric sweetners are possibly by more extensive modification of glucose similar to thio-glucose or sugar sweetner attached to nondigestible polysaccharides such as cellulose. Isomerization of glucose to fructose can provide crystalline fructose which may find wider use in special diet foods. Appropriate derivatization of starch could produce polymers compatible with pure synthetic plastics in which they could act to modify and improve plastic properties.     

Classification of simple and complex sugar adulterants in honey by mid-infrared spectroscopy

Adulteration of honey with sugars is the most crucial quality assurance concern to the honey industry. The application of Fourier transform infrared spectroscopy as a screening tool for the determination of the type of sugar adulterant in honey was investigated. Spectra of honey adulterated with simple and complex sugars were recorded in the mid-infrared range using the attenuated total reflectance accessory of a Fourier transform infrared spectrometer. Adulterants considered were sugars (glucose, fructose and sucrose) and invert sugars (cane invert and beet invert). Predictive models were developed to classify the adulterated honey samples using discriminant analysis. Spectral data were compressed using principal component analysis and partial least-square methods. Linear discriminant analysis was used to discriminate the type of adulterant in three different honey varieties. An optimum classification of 100% was achieved for honey samples adulterated with glucose, fructose, sucrose and beet and cane invert sugars. Results demonstrated that discriminant analysis of the spectra of adulterated honey samples could be used for rapid detection of adulteration in honey.     

蔗糖水解制取结晶果糖技术研究

为提升制糖产业的综合效益,以白砂糖为原料开发附加值更高的结晶果糖,探讨用蔗糖原料制取高纯度结晶果糖的最优工艺方法.实验以高浓度蔗糖液(55％w/w)为原料,食品酸味剂柠檬酸为水解剂,通过蔗糖水解、脱色、阴阳离子树脂除盐,以钙型树脂分离、纯化果葡糖液,在常温下得到结晶果糖和结晶葡萄糖.实验优化蔗糖最佳水解工艺条件:水解温...     

Die Isomerisierung von Hydrol und einige anwendungstechnische Eigenschaften

The Isomerization of Hydrol and Some of Its Applications in Food Industries. Hydrol is a by-product of dextrose manufacture. Its composition and quantities are dependent on the glucose content and the DE of the starch hydrolysate and impurities present. Hydrol can be upgraded by partly isomerising its glucose content to fructose. Experiments of the continuous isomerisation of hydrol with different immobilised glucoseisomerase preparations are described. A high DE syrup (85–88%) with non-crystallising properties and with a relative sweetness of about 75% is obtained. The physico-chemical properties of this isohydrol are described. The sugar spectrum of isohydrol has been determined by sandwich thinlayer chromatography and the oligo- and megalosaccarides up to 18 glucose units have been determined quantitatively. Results of application tests with isohydrol are described. Isohydrol might be used successfully in the production of cookies, fondants, nougat, and also in combination with whipping agents. Isohydrol can substitute saccharose in the production of soft drinks and canned fruits like apple-sauce. A demonstration had been given with various products made with isohydrol.     

CARBON SOURCES AND THEIR EFFECT ON GROWTH, ACETIC ACID AND ETHANOL PRODUCTION BY BRETTANOMYCES BRUXELLENSIS IN BATCH CULTURE

The influence of available low‐cost carbohydrates as carbon sources on Brettanomyces bruxellensis growth, acetic acid and ethanol production was studied in order to ascertain the viability of this yeast to eventually become an industrial acetic acid producer. Six different raw materials were included as carbon sources (glucose, sugarcane molasses, refined cane sugar, pineapple, sugarcane and beet juices). B. bruxellensis develops in a complex culture medium like plant juices and sugarcane molasses better than in a medium with a simple carbohydrate such as glucose. The maximum acid acetic yield (0.24 g/g) and productivity (0.14 g/L/h) were attained in tests carried out with sugarcane molasses containing 60 g/L sucrose. The strain produced low levels of ethanol in a refined sugarcane medium, but was able to produce a substantial quantity of acetic acid (13 g/L).     

Interactions between Zygosaccharomyces mellis and Wallemia sebi in diluted molasses

The yeast Zygosaccharomyces mellis and the mould Wallemia sebi were isolated from the same sample of crystalline sugar. Interactions between these fungi were investigated using a diluted molasses medium (water activity 0.89, pH 6.0) as a model system for the syrup film covering the surface of moist crystalline sugar. Single and mixed cultures of Z. mellis and W. sebi were incubated at 25 degrees C for 400 h. Our results show that the growth of Z. mellis in single culture was limited by available glucose and fructose, and that W sebi was able to invert sucrose to glucose and fructose in both single and mixed culture. Furthermore, the presence of W. sebi in the mixed culture increased the maximum specific growth rate of Z. mellis from 0.074 to 0.19 h(-1) and the growth yield of Z. mellis from 7.3 x 10(6) to 5.4 x 10(7) cfu/ml. These results indicate that the ability of W. sebi to invert sucrose may stimulate the growth of Z. mellis. Finally, the presence of Z. mellis inhibited the ability of W. sebi to invert sucrose: W. sebi was able to invert 1.0 g sucrose/l per h in single culture but only 0.6 g sucrose/l per h in mixed culture. As predicted by Raoults law, this corresponded to a reduction in the water activity of the growth medium from 0.890 to 0.850 in single culture, and to 0.865 in mixed culture.     

一种新型糖源——结晶果葡糖

<正>结晶果葡糖是以玉米淀粉为原料,应用现代生物转化技术和先进的结晶技术而得到的一种淀粉糖,其主要成份是结晶果糖和结晶葡萄糖。该产品具有甜度高、低热量、保湿性好、富含营养、护肝保健、易于运输等特点。结晶果葡糖成为继果葡糖浆、高果糖浆、高纯果糖浆之后的一种工业果糖产品。结晶果葡糖是     

Chitosan from Syncephalastrum racemosum Using Sugar Cane Substrates as Inexpensive Carbon Sources

A strain of Syncephalastrum racemosum isolated from herbivores feces was studied for chitosan production using sugar cane substrates, such as juice or molasses, from Northeast Brazil. S. racemosus was batch grown in shake flasks over 5 days using sugar cane juice or molasses as carbon source. The effect of supplementary nitrogen source was studied by supplying medium with yeast extract or ammonium sulphate. The highest yield of the biopolymer (30 mg chitosan. g^-1 sucrose) was obtained using sugar cane juice (21 g sucrose. L^-1) plus 0.3% yeast extract. Batch fermentation in a 5-L bioreactor using the same medium, increased the yield to 50 mg chitosan. g^-1 sucrose. Chitosan extracted from S. racemosus cultured in sugar cane juice medium showed a low degree of acetylation with a high D-glucosamine content.     

Chitosan from Syncephalastrum racemosum Using Sugar Cane Substrates as Inexpensive Carbon Sources

A strain of Syncephalastrum racemosum isolated from herbivores feces was studied for chitosan production using sugar cane substrates, such as juice or molasses, from Northeast Brazil. S. racemosus was batch grown in shake flasks over 5 days using sugar cane juice or molasses as carbon source. The effect of supplementary nitrogen source was studied by supplying medium with yeast extract or ammonium sulphate. The highest yield of the biopolymer (30 mg chitosan. g^?1 sucrose) was obtained using sugar cane juice (21 g sucrose. L^?1) plus 0.3% yeast extract. Batch fermentation in a 5-L bioreactor using the same medium, increased the yield to 50 mg chitosan. g^?1 sucrose. Chitosan extracted from S. racemosus cultured in sugar cane juice medium showed a low degree of acetylation with a high D-glucosamine content.     

Cultivation of the carotenoid-hyperproducing mutant 2A2N of the red yeast Xanthophyllomyces dendrorhous (Phaffia rhodozyma) with molasses

The carotenoid-hyperproducing mutant 2A2N of the yeast Xanthophyllomyces dendrorhous (Phaffia rhodozyma) was cultivated using sugar beet blackstrap molasses. This molasses was composed of 70% (w/v) total solid and 50% (w/v) total sugar. Biomass yield (biomass/carbohydrate) significantly decreased at >5% (v/v) molasses. Atomic emission spectrometry revealed that Na and P were the limiting nutrients when molasses was used. Molasses (5%, v/v) containing urea (30 g/l molasses) and sodium phosphate (NaH2PO4, 5 g/l molasses) was formulated for biomass production by the mutant. The optimal pH for carotenoid production was 4.9 during the growth phase and 2.6-3.5 during the stationary phase. The three main sugars in molasses (sucrose, glucose, and fructose) were assimilated by the mutant but fructose was consumed slowly. When the formulated medium with pH 4.5-5.5 was used, the maximal biomass yield was 36 g/l (0.18 g of yeast l(-1)h(-1) and 40 mg of carotenoid l(-1)) in fed-batch pilot-scale 100-l cultivation.     

碳源对manA基因突变大肠杆菌代谢的影响

ManA基因编码的甘露糖-6-磷酸异构酶在大肠杆菌中催化D-甘露糖和D-果糖的异构化,促进大肠杆菌对碳源的代谢吸收。本文通过研究manA基因突变大肠杆菌对碳源的利用和编码糖代谢基因情况,探讨甘露糖-6-磷酸异构酶对大肠杆菌糖代谢的影响。采用Ⅱ型内含子逆转录突变方法构建manA基因突变大肠杆菌,分析manA基因突变大肠杆菌对不同碳源的利用情况和manA基因突变对大肠杆菌糖代谢相关基因表达的影响,结果显示,大肠杆菌BL21(DE3)ΔmanA以甘露糖、果糖为碳源时,菌株生长受到显著抑制;以淀粉为碳源时,BL21(DE3)ΔmanA菌株的生长显著优于野生型大肠杆菌;以葡萄糖为碳源时,manA基因突变对大肠杆菌的生长无显著影响。通过基因表达分析,发现大肠杆菌BL21(DE3)ΔmanA中甘露糖代谢相关基因的表达显著性降低;果糖代谢途径中6-磷酸果糖激酶Ⅰ亚基的编码基因(pfkA)显著下调表达;水解淀粉的α-淀粉酶编码基因(malS)显著性上调表达。ManA基因突变影响大肠杆菌甘露糖、果糖和淀粉代谢途径中相关基因的表达,从而影响大肠杆菌对碳源的利用。     

Separation of Sucrose and Reducing Sugar in Cane Molasses by Nanofiltration

Recovery of sugars from cane molasses is a promising approach to increase the added value of molasses and reduce its environmental pollution. In this work, for the first time, nanofiltration (NF) was used for the separation of sucrose and reducing sugar in cane molasses by a cascade diafiltration-concentration process. The retention difference between sucrose and reducing sugar by all the tested NF membranes was not distinct at 25 °C, while due to the thermal-induced pore size change and enhanced solute diffusivity, the NF retention behavior changed significantly at 60 °C, and the DL membrane with a sucrose retention of 96% and a reducing sugar retention 5% was selected for the process optimization and modeling. High temperature (55–60 °C), low permeate flux (below 15 Lm^?2 h^?1), and high sugar concentration resulted in a low retention of reducing sugar due to the dominant diffusive mass transfer, which was desirable for the molasses separation by NF. Mathematical modeling could well predict the diafiltration and concentration processes if using right sugar retention data. The deviations between prediction lines and experimental data in the cross-flow filtration of real solution were mainly caused by the permeate flux variation rather than membrane fouling. After diafiltration, the ratio of sucrose in total molasses sugar increased from 76.1 to 87.9%, while in the permeate of the second concentration step, the ratio of sucrose was only 2.4%. Thus, the retentate of diafiltration could be directly used for sucrose crystallization to avoid the accumulation of reducing sugar and salts, and the permeate of the second concentration step could be concentrated by NF270 at room temperature to produce syrup drinking.     

Limonoid Debittering of Citrus Juice Sera By Immobilized Cells of Corynebacterium fascians

Corynebacterium fascians cells capable of metabolizing limonoids were prepared conveniently with inexpensive carbon sources such as fructose, galactose and citric acid. Cells thus obtained were immo-bilized in acrylamide gel and used in a biological debittering process previously developed. The process significantly reduced limonin and nomilin contents of citrus juice sera. It was particularly effective toward the reduction of nomilin. The debittering treatment did not have adverse effects on the composition of other citrus constituents such as citric, malic, ascorbic acids, fructose, glucose and sucrose.     

ISOLATION AND SELECTION OF ETHANOL-RESISTANT AND OSMOTOLERANT YEASTS FROM REGIONAL AGRICULTURAL SOURCES IN MEXICO

In Mexican alcohol distilleries using sugarcane molasses, one reason for low alcoholic fermentation efficiency is the use of inferior yeast cultures. The objective of the present study was to isolate and select yeast strains from alcoholic fermentations of natural sources (sugarcane molasses, grape juice, cane juice and pineapple) from Veracruz city market and Mexican distilleries, and to evaluate their performance under laboratory conditions in an effort to select superior strains for industrial fermentations. Ethanol production, glucose composition, growth rate, "Killer" activity, ethanol and glucose tolerance of the most promising strains were monitored on synthetic and molasses media. A total of 112 yeast strains were isolated by their capacity to produce ethanol, and from these, only 58 were selected on the basis of best ethanol theoretical yields (88–96%). These strains were exposed several times to high concentrations of glucose and ethanol in order to select ethanol- and glucose-tolerant yeast; 10 were obtained that adapted best to these conditions and that showed "Killer" activity. Of these strains, U3-11, M11, JC10 and U2-10 (obtained from grape juice, sugarcane molasses and cane juice) demonstrated the highest adaptation to both ethanol (5–7% w/v) and glucose (20% w/v). The maximum yield obtained was 0.46 g/g (90% theoretical yield) in a 20-L bioreactor with cane molasses under nonsterile conditions.

PRACTICAL APPLICATIONS

The selected yeasts could be introduced into industrial processes in Mexican distilleries using sugarcane molasses in order to improve productivity and diminish contamination problems.     

Use of the Rapid-Visco-Analyzer to Measure Starch Pasting Properties. Part I: Effect of Sugars

The Rapid Visco-Analyzer (RVA) was used to measure the effects of dextrose, sucrose, corn syrup solids and polydextrose on maize, tapioca and wheat starch pasting properties. The addition of 1 part sugar: 1 part starch tended to decrease peak viscosity, whereas peak viscosity increased at higher sugar concentrations (up to 4 parts sugar: 1 part starch). Time to onset of viscosity increase and time to peak viscosity increased as sugar concentrations increased. Dextrose, sucrose and corn syrup solids increased the maximum setback viscosity, of the starches, but polydextrose reduced setback viscosity. As the molecular weights of the sugars increased, the effects generally increased for maize and tapioca starches but not for wheat starch. Pasting property parameters measured in the RVA concurred with data obtained using other viscometers or by other techniques previously reported. The RVA is useful as an alternative tool for studying starch pasting properties and the effects of food ingredients on starch performance.     

Fermentation by Lactobacillus fermentum Ogi E1 of different combinations of carbohydrates occurring naturally in cereals: consequences on growth energetics and alpha-amylase production

Glucose, fructose, sucrose and starch are naturally present in cereals. Fermentation of different combinations of these carbohydrates by Lactobacillus fermentum Ogi E1, a sourdough heterofermentative lactobacillus, was investigated to determine effects on fermentation kinetics, growth energetics and alpha-amylase production. Irrespective of the substrate combination, the strain was able to simultaneously produce alpha-amylase and consume starch, glucose, fructose and sucrose. In mixtures of starch with either sucrose or fructose or with both fructose and glucose, yields of alpha-amylase from biomass (Y(amy/x)) were similar to those observed for starch. However, for starch and glucose or starch, glucose, fructose and sucrose mixtures, both Y(amy/x) and the specific rate of alpha-amylase production decreased markedly. In fructose- or sucrose-containing mixtures, mannitol was formed stoichiometrically indicating that fructose served as electron acceptor, and acetate was produced at constant yield from biomass (Y(ac/x)) (1 g acetate g biomass(-1)). Acetate production was expected to confer to the strain a competitive advantage during natural fermentation by improving biomass formation and growth through an increase in the ATP gain. Y(ATP) varied depending on the carbohydrate mixture, indicating different effects of substrate mixtures on the efficiency in ATP coupling to biomass formation. Compared to starch fermentation, the highest value of Y(ATP) (29 g biomass mol ATP(-1)) was estimated for the starch/fructose mixture but no increase in mu(max) was observed. The lowest value (16 g biomass mol ATP(-1)) was obtained for the starch, glucose and fructose mixture, whereas for the mixture of all carbohydrates, Y(ATP) was similar to that obtained with starch alone (20 g biomass mol ATP(-1)) and it was intermediary for the starch and sucrose mixture (17 g biomass mol ATP(-1)). It is concluded that competitiveness of the strain cannot be based on expected energy gain in mixed substrate fermentation involving fructose and sucrose with glucose and starch, but rather on its ability to simultaneously use carbohydrates while producing alpha-amylase and to produce acetic acid. Acetic acid production could enhance the strain capacity to inhibit nonacid-tolerant, competitive microflora at the earlier stage of natural fermentation.     

磷酸单酯淀粉糊透明度影响因素的研究

研究了磷酸单酯淀粉的透明度以及NaCl、蔗糖、柠檬酸等食品成分和老化作用对透明度的影响。结果表明，NaCl对淀粉糊的透明度影响不大，而蔗糖、柠檬酸则能提高糊液的透明度，老化使淀粉糊的透明度下降，初期下降迅速，中后期下降减缓。     

Improved quantitative ion chromatography of industrial sugars: removal of interfering amino acids

The effect of interfering amino acids on the accurate quantitation of sugars in sugar industry samples, using ion chromatography with integrated pulsed amperometric detection (IC-IPAD), was investigated. Industrial sugar samples included beet syrup, juice and molasses samples. Using sugar and amino acid standard mixtures, and industrial sugar samples, proline was found to co-elute with fructose and serine with sucrose, and both co-elutions were “additive”, which caused both fructose and sucrose to be overestimated. Conversely, the co-elution of arginine with myo-inositol, and glutamine with glucose had a marked “suppressive” effect on sugar quantitation and both myo-inositol and glucose were underestimated. Various methods were investigated for their efficiency to remove interfering amino acids, but not remove sugars: prefiltering of dilute samples through cation exchange syringe filters proved the most efficient method. Using sugar and amino acid standard mixtures, within experimental error, the cation exchange filter restored the mean concentrations of myo-inositol, glucose and sucrose to expected values, and standard deviations for all sugars were reduced markedly. Removal of interfering amino acids in a beet juice from a sweet water tank caused increases in mean concentrations for myo-inositol (+4.2%) and particularly for glucose (+62.5%), and a decrease for fructose (−7.3%). ©     

Production of L-lactic acid from fresh cassava roots slurried with tofu liquid waste by Streptococcus bovis

To reduce the production cost of biodegradable plastics, the fermentation performance of L-lactic acid for a new fermentation medium, fresh cassava roots (FCRs) as a substrate slurried with tofu liquid waste (TLW) as basal medium, was investigated by batch fermentation of Streptococcus bovis. The fermentation properties of the three substrates, namely, FCR, tapioca (cassava starch) and glucose, which were independently mixed with TLW, were compared with those independently mixed with the standard basal medium, trypto-soya broth (TSB). Experiments were conducted at various sugar concentrations of the substrates with CaCO(3) as a neutralizer. The maximum L-lactic acid concentrations (C(La)) obtained using the three substrates in TLW were about 75% of those obtained using TSB caused by less nutrients in the TLW. The L-lactic acid productivities (P(La)) and the specific growth rates of S. bovis (mu) in TLW were about 1/4 to 1/3 and 1/5 to 1/4 of those in TSB, respectively. The maximum C(La), P(La) and mu were obtained at 10% w/w sugar concentration. Total yields (eta) were nearly constant up to 10% w/w sugar concentration for TSB and TLW, that is, 80% to 85% and 50% to 60%, respectively. But their total yields decreased in more than 10% w/w sugar concentration in both basal media, because of substrate inhibition. The fermentation properties (C(La), P(La), mu, and eta) were found to be in the order of: FCR > tapioca > glucose for all concentrations of the three substrates. The fermentation properties for FCR and tapioca were higher than those for glucose, in TLW or TSB, because S. bovis in a medium containing starch (FCR and tapioca) has more amylase activity than in a medium containing glucose. The nutrients in FCR with poor nutrient basal medium (TLW) more strongly affected the fermentation properties than those in FCR with rich nutrient basal medium (TSB). The proposed fermentation medium of FCR slurried with TLW is worth studying in order to reduce production cost of biodegradable plastics.