Determination Of Reducing Sugars Research Articles

Total Phenolic and Starch Content of Arrowroot Tuber in The Agroforestry System

Indonesia's tropical forest management faces several challenges owing to the growing demand for forest resources and increasing population. The forestry sector plays a significant role in supporting food security programs by harnessing the potential of forest resources. One solution to sustainable forest management and optimal forest land use is agroforestry techniques. Arrowroot (Maranta arundinacea) is tolerant to heavy shade and is a promising functional food crop that can contribute to food security programs. Starch content in arrowroot tuber plays an important role in meeting nutritional requirements and overcoming several health problems. Arrowroot tubers also contain phenolic compounds, the largest group of compounds that act as natural antioxidants in plants. This study aimed to analyze the total phenolic and starch contents of arrowroot tubers cultivated in agroforestry systems. We used a Randomized Complete Block Design with a planting pattern as treatment for the species combinations of Falcataria moluccana + arrowroot (FA), F. moluccana + arrowroot + Amomum cardamomum (FAC), and monoculture arrowroot (MA) with three blocks/replications. The arrowroot tubers were harvested from nine-month-old plants and composite samples representing each treatment were analyzed for total phenolic and starch contents. The total phenolic content in the arrowroot tubers was determined using the Folin-Ciocalteu reagent. Starch content was measured using the Modified Somogyi method, which involves preparing reagents, followed by hydrolysis and the reducing sugar determination methods. The results revealed that the planting pattern significantly affected starch content. The highest starch content was observed in the MA pattern of 23.99%, followed by the FAC and FA planting patterns of 22.75% and 18.44%, respectively. The planting pattern did not significantly affect phenolic content. The MA, FAC, and FA patterns yielded the highest to lowest phenolic contents of 218.02, 212.62, and 210.04 µg/g, respectively. Furthermore, the planting pattern significantly affected the total phenolic of tuber yield per plant, with the highest value of 214.48 mg yielded by MA pattern. Thus, agroforestry practices can maintain the phenolic and starch content of arrowroot tubers. The development of arrowroot in agroforestry system will be prospective not only for meeting food demand, but also for supporting forestry multi-business and social forestry programs to achieve sustainable forest management.

Simple and cost-effective approaches for quantification of reducing sugar exploiting digital image analysis

Simple, low-cost, and fast analytical procedures for reducing sugar quantification in beverages are proposed by digital image analysis. The procedures are based on the colorimetric spot test reaction of the analyte with 3,5-dinitrosalicylic acid (DNS method) and its oxidation by the cupric ion (Cu 2+ ) (Benedict method). Digital images were acquired using a flatbed scanner and converted to RGB values. Values of channel G and R were taken as analytical responses for DNS and Benedict method, respectively, because of the complementarity with the color of the reaction product. Linear responses were observed in the glucose concentration range between 0.10 and 0.30 g L −1 , with a detection limit of 2.9 × 10 −2 g L −1 for the DNS method and from 1.0 to 5.0 g L −1 , with a detection limit of 0.5 g L −1 for the Benedict method. Recovery values between 97% and 103% were obtained in the addition and recovery experiments for both procedures. These analytical procedures were applied to different beverage samples (juice, coconut water, and sugar cane spirits) and the results were in close agreement with those obtained using a reference method, with a confidence level of 95%. • Simple and cost-effective procedures for reducing sugar determination in beverages. • Exploiting of DNS and Benedict colorimetric methods. • Environmentally friendly procedure exploiting 96-well microplate. • Detection based on digital images obtained with a commercial flatbed scanner.

The mechanism by which Enteromorpha Linza polysaccharide promotes Bacillus subtilis growth and nitrate removal

In this study, we discussed the relationship between Entermorpha linza polysaccharide (EP) and Bacillus subtilis, which can transform nitrate. A sole carbon source experiment showed that Bacillus subtilis could utilize EP, and the bacterial density was maximally increased by 54.43% in the EP groups. The results of reducing sugar determination proved the secretion of polysaccharide-degrading enzymes. Scanning electron microscopy (SEM) showed that the EP groups had fewer spores and shrunken bacteria, indicating that EP could improve the growth environment and maintain bacterial integrity. Additionally, the ratios of periplasmic nitrate reductase (NAP), nitrite reductase (NIR), and dissimilatory nitrate reductase (D-NRase) in the EP groups were maximally increased by 107.22%, 84.70% and 36.10%, respectively. Transcriptome analysis further confirmed the above mentioned results. For example, the high expression of quorum sensing genes indicated that EP groups had higher bacterial density. Moreover, the high expression of antioxidant genes in the EP groups may be related to morphological integrity. Our study provides a basis for further discussion of the mechanism.

Preliminary Study of Biohydrolysis Method of Durian Rind for Reducing Sugar Determination on Bioethanol Production

Biohidrolisis merupakan proses hidrolisis atau delignifikasi biomasa lignoselulosa secara enzimatik dengan bantuan mikroorganisme. Koleksi isolat cendawan Trametes polyzona dan Aspergillus sp. memiliki potensi untuk digunakan pada proses biohidrolisis dalam produksi bioetanol. Penelitian ini dilakukan untuk mengetahui potensi isolat cendawan dalam metode biohidrolisis kulit buah durian untuk pembentukan gula reduksi dalam produksi bioetanol. Optimasi metode dilakukan dengan perlakuan biohidrolisis langsung dengan cendawan, kombinasi praperlakuan kimiawi (1% NaOH) dan biohidrolisis, kombinasi praperlakuan panas (microwave) dan biohidrolisis, serta delignifikasi alkali (5% NaOH) sebagai kontrol. Isolat cendawan Trametes polyzona secara umum memperlihatkan potensi terbaik pada perlakuan biohidrolisis langsung maupun kombinasi dengan praperlakuan kimia dan panas dibandingkan dengan isolat Aspergillus sp. Proses biohidrolisis Trametes polyzona dengan kombinasi praperlakuan panas selama 10 menit dengan inkubasi selama 7 hari menghasilkan 0.38% atau setara 3.83 g L-1 gula reduksi pada hidrolisat. Metode biohidrolisis langsung memberikan hasil 0.32% dan tidak berbeda nyata dengan kontrol (0.32%). Kedua modifikasi dalam proses hidrolisis biomasa lignoselulosa ini dapat digunakan sebagai metode alternatif produksi bioetanol di samping menggunakan senyawa kimia. Metode biohidrolisis dengan cendawan Trametes polyzona ini masih perlu dikaji lebih dalam terkait beberapa parameter lainnya yang berpengaruh agar diperoleh gula reduksi yang lebih baik dalam produksi bioetanol yang lebih efektif.
 Kata kunci: delignifikasi, lignoselulosa, optimasi, Trametes polyzona
 
 
 
 

Fontes de fertilizantes potássicos na qualidade dos tubérculos de batata

A resposta da batateira à adição de nutrientes ao solo proporciona relevante atenção, especialmente a adubação com potássio (K), por ser um elemento que interfere na composição dos tubérculos, consequentemente em sua qualidade. O cloro, presente na principal fonte de K para as plantas (KCl), pode gerar efeito negativo em atributos relacionados a qualidade dos tubérculos. Neste sentido, objetivou-se avaliar a influência de duas fontes de fertilizante potássico (KCl e K2SO4.2MgSO4) e combinações entre elas na composição dos tubérculos de batata, cv. Asterix. A quantidade de N, P e K utilizada foi determinada mediante análise de solo e necessidade da cultura. A determinação dos glicídios redutores foi realizada segundo o método espectrofotométrico (Somogyi-Nelson), já os Glicídios totais e o amido, pelo método de Lane Eyno (titulométrico). A maior massa seca e amido na cultivar Asterix está relacionada à aplicação de 26.3% de KCl e 73.7% de K2SO4.2MgSO4 e 41.9% de KCl e 58.1% de K2SO4.2MgSO4, respectivamente. Assim, a combinação das fontes é indicada para promover maior teor dessas qualidades nos tubérculos. Por outro lado, fontes e proporções, de fertilizantes potássicos não interferem na composição dos açúcares. A taxa usada neste estudo (180 kg ha-1) provavelmente não foi suficiente para refletir o efeito deletério do cloro nos constituintes de açúcares dos tubérculos.
 Palavras-chave: Solanum tuberosum L., cultivar Asterix, cloreto de potássio, sulfato duplo de potássio e magnésio.

Alternative method of reducing sugars determination in some selected fizzy drinks and fruits by chromic acid reagent

Chromic acid reagent as an alternative colorimetric method for the quantitative determination of reducing sugars and ascorbic acid in some selected fizzy drinks: Seven Up, Limca, Mirinda, Cocoa-Cola, Fanta, Pepsi Cola, Maltina, Guinness Malt, Hi-Malt and Maltonic) and fruits: pineapple (Ananas cosmoses), sweet orange (Cimifi sinensis), grape fruit (Dints paradise) and tangerine (Citrus reticulate) has been studied. Chromic method involves sugar solution of about 1% concentration. treated with an equal volume of concentrated nitric acid and a few drops of a 5% solution of potassium dichromate was added, a blue colour develops in less than a minute in the cold and the absorbance taken in a Spectronic 20D Spectrophotometer at 560 um. Results obtained from the simple chromic acid as test method compares well with those obtained from the titrimetric methods of Association of Official Analytical Chemists (AOAC, 2012) and Pearson (1991) as control, with negligible variations. Apart from being a very powerful oxidizing agent, its reaction with monosaccharide, disaccharides and ascorbic acid are less-time consuming, showed distinct colour development and its easy preparation, made chromic acid reagent a faster, better and suitable alternative method for the quantitative determination of reducing sugars and ascorbic acid in routine analyses of foods.
 Keywords: reducing sugar, ascorbic acid, chromic reagent.

DETERMINATION OF SIMPLE SUGARS IN MEDICINAL PLANT MATERIALS BY THE METHOD OF HIGH-PERFORMANCE THIN-LAYER CHROMATOGRAPHY (FOR EXAMPLE, THE FRUITS OF SEA BUCKTHORN L. AND NETTLE LEAVES L.)

An analysis of the literature over the past 20 years has shown that when controlling the quality of drugs containing monosaccharides, as well as studying the composition of simple sugars in polysaccharide complexes of medicinal plants and not only, preference is given to physicochemical methods, as the most express, sensitive and informative. No means have been found in the scientific literature to identify and quantify simultaneously various monosaccharides by high performance thin layer chromatography (HPTLC). An economical and rapid method has been developed for the identification and quantitative determination of simple reducing sugars (by the example of glucose, rhamnose and xylose) by the HPTLC method. The optimal conditions for their chromatography in a thin layer of sorbent with a quantitative interpretation of HPTLC data on a personal computer were experimentally selected and theoretically substantiated. In a detailed study of the influence of the polarity of the system on the value of Rf, the intervals of values of the polarity of the eluent were chosen, in which these dependences become linear. Using the proposed dependencies, you can select different systems for the separation of monosaccharides in a thin layer of sorbent, so that the value of Rf fit into the optimal values. The proposed method was tested on medicinal plant raw materials of nettle dioica and sea buckthorn fruits of various conservation methods. Zones of simple sugars of characteristic color were found on the chromatograms of extracts from the studied raw materials, among which glucose, xylose and rhamnose were identified by the characteristic value of Rf values in comparison with reliable standard samples. The technique can be used in quality control of substances, single-component and complex preparations, plant objects, dietary supplements, premixes and products of the food industry.

Galvanostatic electrodeposition of copper nanoparticles on screen-printed carbon electrodes and their application for reducing sugars determination

In this work, a novel method for the galvanostatic electrodeposition of copper nanoparticles on screen-printed carbon electrodes was developed. Nanoparticles of spherical morphology with sizes between 60 and 280nm were obtained. The electrocatalytic effect of these copper nanospheres towards the oxidation of different sugars was studied. Excellent analytical performance was obtained with the nanostructured sensor: low detection limits and wide linear ranges (1–10,000µM) were achieving for the different reducing sugars evaluated (glucose, fructose, arabinose, galactose, mannose, xylose) with very similar calibration slopes, which demonstrates the possibility of total sugar detection. The reproducibility of these sensors was 4.4% (intra-electrode) and 7.2% (inter-electrode). The stability of the nanostructured electrodes was at least 30 days, even using the same device on different days. Several real samples (honey, orange juice and normal and sugar-free soft drinks) were evaluated to study the reliability of the nanostructured sensor.

Efficiency of acetic acid and formic acid as a catalyst in catalytical and mechanocatalytical pretreatment of barley straw

In this study, the potential of organic acids (formic acid, acetic acid) in a catalytical and mechanocatalytic conversion of lignocellulosic barley straw to valuable sugars is explored using sulfuric acid as a reference. Acid-catalyzed hydrolysis has been carried out with acid-impregnated samples as well as unmodified barley straw. In the mechanocatalytical approach, pretreatment consists of impregnation with the acid catalyst and mechanical treatment by ball milling following chemical hydrolysis. Straw samples and residues were analyzed by Fourier transform infrared spectrometry (FT-IR) whereas hydrolysate analysis was based on total reducing sugar (TRS) determination following the DNS method and capillary electrophoresis (CE) analysis. The results indicated that acetic acid and formic acid are rather mild acids yielding low TRS levels compared to the reference acid. Mechanocatalytical pretreatment slightly increased TRS yields, but not significantly. Strikingly, sulfuric acid showed an efficient conversion efficiency yielding almost 45% of TRS. Furthermore, this study provided evidence for the acetylation of straw components when acetic acid was used as catalyst. Alkali hydrolysis induced the de-esterification, but revealed no significant increase of TRS yields.

Electrochemical determination of total reducing sugars from bioethanol production using glassy carbon electrode modified with graphene oxide containing copper nanoparticles

This work presents the analytical method development for total reducing sugars determination in residual water samples obtained from sugarcane processing for ethanol production. This method was developed using pulsed amperometry with a glassy carbon electrode modified with graphene oxide containing copper nanoparticles. With pulsed amperometry detection was achieved a limit of detection of 6.4×10−6molL−1. The amperometric sensitivity was 1.6×10−2Amol−1L. The recovery study showed that the method has good accuracy and repeatability, with recovery of 92.8±0.5%. Experiment results obtained showed that the sensor has good long-term stability, sensitivity and is interference free, and the method developed is simple and fast.

알긴산이 Nannochloropsis oculata NIES-2145의 생장에 미치는 영향

The growth effect of Nannochloropsis oculata (N.oculata), unicellular microalgae, by alginate was investigated. Alginate was depolymerized with sulfuric acid (<TEX>$H_2SO_4$</TEX>) and heat (<TEX>$121^{\circ}C$</TEX>), simultaneously. Addition of 0.75% alginate oligomer depolymerized with 0.2 N <TEX>$H_2SO_4$</TEX> showed the maximum yield and the growth rate of N. oculata. Chlorophyll content and reducing sugar was increased by alginate oligomer in a dose-dependent manner. Alginate oligomer promoted the growth of N. oculata, whereas the original alginate polysaccharides had no significant effect. Laminaria japonica (L. japonica) extract containing high level of alginate was also increased growth rate and chlorophyll content. <TEX>$CO_2$</TEX> supply addition to L. japonica extract showed no change the growth rate, although addition to alginate oligomer showed prominently increased. N. oculata could use more saccharides in presence of <TEX>$CO_2$</TEX> according to reducing sugar determination. From these results, it is useful to establish optimal condition for high cell density cultivation of N. oculata.

Adaptation of dinitrosalicylic acid method to microtiter plates

A microtiter plate adaptation of the well-known dinitrosalicylic acid (DNS) colorimetric method, for measurement of reducing sugars, is described. This method allows a substantial volume reduction of the reagents and a rapid analysis of a large number of samples, having an economic cost benefit and a positive impact on the environment. Therefore, it is well suited as an high-throughput technique for reducing sugars determination.

COMPARISON AND EVALUATION OF PHYSICOCHEMICAL PROPERTIES AND ADULTERATIONS IN PRODUCED HONEYS OF SHIRAZ PROVINCE IN DIFFERENT SEASONS

Honey is a plant extract that is gathered with bee and saved in comb after some modification. The apparent properties of honey, for example color, flavor and concentration, depend on rearing region of bee, climate and harvest season. The aim of this study was to investigate quality and adulteration in honeys that were presented in shiraz province. 96 samples of honey during 4 seasons (2007-2008) were collected. All the samples were evaluated by some tests such as diagnosis of artificial sugar, diastase activity, Hydroxy Methyl Furfural (HMF), determination of reducing sugars, saccharose, fructose to glucose ratio, pH, free acidity, moisture, ash, electrical conductivity, Suspended Solids (S.S) and deviation of polarized light. After statistical analysis of data, we concluded that in spring, summer, autumn and winter seasons, 25%, 37.5%, 16.7% and 48.53% of honey samples and totally %31.25 of whole samples of honey was recited is in a way of spurious. According to this results, it is proposed that using simple, fast, cheap and reliable laboratory methods for studying of adulterations in honeys that were presented (traditional and factorial packed) and following by related organization to prevent these instances. Key Words: Honey, Adulteration, Season, Physicochemical properties.

Exploiting Pulsed Flows for Heating Improvement: Application to Determination of Total Reducing Sugars in Molasses and Sugar-Cane Juices

Laminar and pulsed flows typical of multi-commuted and multi-pumping flow systems, were evaluated in relation to analytical procedures carried out at high temperatures. As application, the spectrophotometric determination of total reducing sugars (TRS, hydrolyzed sucrose plus reducing sugars) in sugar-cane juice and molasses was selected. The method involves in-line hydrolysis of sucrose and alkaline degradation of the reducing sugars at about 98 °C. Better results were obtained with pulsed flows, due to the efficient radial mass transport inherent to the multi-pumping flow system. The proposed system presents favorable characteristics of ruggedness, analytical precision (r.s.d. < 0.013 for typical samples), stability (no measurable baseline drift during 4-h working periods), linearity of the analytical curve (r > 0.992, n = 5, 0.05 - 0.50% w/v TRS) and sampling rate (65 h-1). Results are in agreement with ion chromatography. Keywords: Multi-pumping flow analysis, Pulsed flow, Laminar flow, Heat transference, Total reducing sugars, Sugar-cane juice and molasses, Spectrophotometry

Conversion of Fibrous Sago (Metroxylon sagu) Waste into Fermentable Sugar via Acid and Enzymatic Hydrolysis

The hydrolysis of dried-powdered fibrous sago waste by sulphuric acid and glucoamylase was studied. Both studies were carried out in an Erlenmeyer flask placed in a controlled temperature water bath. Samples were taken from the reaction flask at every 30 min interval for reducing sugar determination. The optimum condition for acid hydrolysis was found to be at 90°C, using 1.5 M acid concentration and reaction time of 120 min yielding 0.6234 g glucose g-1 waste. The kinetic parameters of acid hydrolysis in the Saeman`s model, were the rate constant (k1 = 0.01405 (1/min)), activation energy (Ea =120.40 (kJ mol-1)) and pre-exponential factor (A = 9.52x1016 (1/min)). The optimum condition for enzymatic hydrolysis using glucoamylase was found to be at enzyme concentration of 6 AGU mL-1 and reaction time of 30 min, yielding 0.5646 g glucose g-1 waste. The kinetic parameters in the competitive inhibition model corresponding to the optimum condition, namely the equilibrium constant for enzyme-inhibitor complex, Michaelis-Menten constant and maximum velocity, are 1.4727, 0.24175 and 1.35460 g L-1.min, respectively.

Herança de acilaçúcares em genótipos de tomateiro provenientes de cruzamento interespecífico

O objetivo deste trabalho foi determinar a herança da produção de acilaçúcares em genótipos de tomateiro, em uma população segregante (F2) do terceiro retrocruzamento, para Lycopersicon esculentum Mill. 'TOM-584', a partir da espécie L. pennellii 'LA-716'. A determinação do teor de acilaçúcares foi realizada com metodologia para determinação de açúcares redutores. Os dados foram utilizados para verificação da herança monogênica, sob diferentes graus de dominância (GD) presumidos, por meio do teste qui-quadrado. Para verificar a existência de efeitos aditivos e não aditivos de um gene maior e de possíveis poligenes, utilizou-se o método da máxima verossimilhança. Para os diferentes GD testados, na faixa compreendida entre -0,7 e -0,4, a hipótese de herança monogênica não pôde ser descartada, o que indica a ação de alelo recessivo, com dominância incompleta na expressão de alto teor de acilaçúcares. Por meio de modelos genéticos pela função de verossimilhança, a hipótese de herança monogênica foi confirmada. Plantas de tomateiro, com boa resistência a artrópodos-praga, mediada pelo aleloquímico acilaçúcar, podem ser obtidas com eficiência em populações de retrocruzamentos, a partir do cruzamento interespecífico L. esculentum x L. pennellii.

Dairy shed wastewater treatment and modelling by anaerobic digestion technology

There is a growing interest in the application of Anaerobic Digestion (AD) technology to Australian dairy farms not only for the reduction of environmental pollution caused by the effluents but also for recovering bioenergy. To be able to design and operate efficient AD systems, appropriate mathematical models need to be developed to observe and analyse the anaerobic process dynamics, such as the Anaerobic Digestion Model No. 1 (ADM1) model developed by IWA Task Group. However, it has not been applied into various digester configurations to treat dairy shed wastewater originating from hydraulic flood systems that are used in typical Australian farms. In this paper, a critical review of AD technology in the context of Australian conditions and the application of ADM1 model has been described. Batch experiments were conducted to characterise the Australian dairy shed wastewater. New analytical methods for determination of Volatile Fatty Acids (VFAs) and total reducing sugar are further developed.

Determination of apparent reducing sugars, moisture and acidity in honey by attenuated total reflectance-Fourier transform infrared spectrometry

Attenuated total reflectance-Fourier transform infrared spectrometry, in conjunction with multivariate calibration, was used for determination of reducing sugars, humidity and acidity in honey bee samples. Multivariate calibration models were built using partial least squares (PLS) and were refined through variable selection per interval (iPLS) and genetic algorithms. The calibration models show satisfactory results for all parameters with average relative errors of 6% for acidity, 1% for reducing sugars and 2% for humidity. For the acidity and reducing sugars parameters, variable selection was irrelevant, but for humidity it was essential. For the humidity parameter, it was necessary to use two variable selection techniques (by intervals and genetic algorithm) concomitantly in order to obtain a satisfactory calibration model.

Spectrophotometric flow-injection determination of total reducing sugars exploiting their alkaline degradation

An automated procedure exploiting alkaline degradation of carbohydrates is proposed for spectrophotometric determination of total reducing sugars, TRS (hydrolyzed sucrose plus reducing sugars), in samples relevant to the sugar industry. An environmental friendly reagent is used instead of the commonly used toxic (e.g. arsenate) or expensive (e.g. enzymes) reagents. The analytical steps of acidic sucrose hydrolysis and sugar alkaline degradation are in-line accomplished at about 95 °C. The formed colored solution is then spectrophotometrically monitored at 450 nm. The proposed system handles 60 samples per hour, and yields precise results, relative standard deviation being estimated as <5% for a typical sample (1.24%, w/v, TRS). Baseline drift has been not verified during 8-h working periods, emphasizing the system ruggedness. A linear response is observed between 0.1 and 2.0% (w/v) TRS. Results are in agreement with HPIC.

A critical assessment of a viscometric assay for measuring Saccharomycopsis fibuligera α-amylase activity on gelatinised cassava starch

A viscometric technique for measuring Saccharomycopsis fibuligera DSM-70554 α-amylase on gelatinised cassava starch aqueous solutions was assessed. The selected conditions for working over a reliable viscosity measurement range involved a starch concentration of 5% (w/v) and a shear rate of 0.168 1/s. Viscometric assay involved the determination of the slope of the decrease in viscosity with time of the starch solution consequent on enzyme addition. Thereafter, a calibration curve was constructed by plotting the slopes, expressed in arbitrary viscometric units (AVU), versus the corresponding absolute activity (in IU) of either the commercial α-amylase from Aspergillus oryzae (up to 0.1 IU) or the S. fibuligera DSM-70554 α-amylase (up to ca. 0.4 IU). The amount of enzyme expressed in absolute terms produced different liquefying activities according to the α-amylase tested, emphasising the necessity of this correlation to be carried out for the particular enzyme being measured. In this work, a linear relationship and a very good correlation factor were achieved for the calibration of both amylases. Likewise, α-amylase activities determined according to the conventional reducing sugar determination and the colorimetric assay with iodine were proportional to those viscometrically obtained, both for A. oryzae and S. fibuligera α-amylase, validating conversions between different units. The viscometric assay herein described showed to be specific and sensitive and, after its calibration, it allows to convert α-amylase measurements in absolute units thus facilitating future comparisons.