A simple colorimetric method for the determination of sugars in fruit and vegetables

Blakeney, A. B.; Mutton, Lachlan L.

doi:10.1002/jsfa.2740310905

Cited by 211 publications

(125 citation statements)

References 8 publications

Supporting

Mentioning

125

Contrasting

Order By: Relevance

“…The chemical determination of values for the NIR calibrations was obtained by the Kjeldahl (Bradstreet, 1965) method for N and the thiobarbituric acid method for fructan (Percheron, 1962;Blakeney & Mutton, 1980;Pontis, 1990). This method is specific for ketohexoses, and the total apparent fructose determined is used as a measure of fructan content.…”

Section: Methodsmentioning

confidence: 99%

“…This method is specific for ketohexoses, and the total apparent fructose determined is used as a measure of fructan content. Monosaccharides and sucrose can be determined and deducted (Blakeney & Mutton, 1980) or destroyed (Pontis, 1966). The ballmilled plant sample (0-1 g) is extracted in diammonium phosphate solution (20 ml, 50 mM), mixed and heated for 20 min with two further vortex mixings, then filtered through W^hatman No.…”

Section: Methodsmentioning

confidence: 99%

See 1 more Smart Citation

Fructan to nitrogen ratio as an indicator of nutrient stress in wheat crops

McGRATH¹,

BLAKENEY²,

Batten³

1997

New Phytologist

View full text Add to dashboard Cite

SUMMARYWheat stems serve as a store for fructans to buffer the plant against nutritional and environmental infiuences. It has been suggested that fructan storage influences yield stability and tolerance of environmental factors. Near infrared spectroscopy (NIR) analysis provides a rapid and accurate assessment of the fructan content of the wheat stem, as well as allowing detection of growth-limiting nutrient stresses, and so is proving to be a useful technique for making crop management decisions. Commercial laboratories using NIR analysis have been tissue-testing crops in the eastern Australian wheat belt since 1993. In healthy, normally developing crops not under stress there is a predictable relationship between nitrogen and fructan. Investigation of the nitrogen and fructan concentrations in commercial crops has confirmed an inverse relationship between these two constituents. The function: Fructan (%) = a + 6N%-|-cN%^ accounted for up to 81% of variation in tissue fructan concentration. In commercial tissue-testing this relationship is used to detect crops under stresses other than nitrogen deficiency. If the fructan concentration deviates by more than 4 %, cereal growers are advised that their crop might be subject to other stresses which might reduce its response to applied nitrogen.

show abstract

Section: Methodsmentioning

confidence: 99%

Section: Methodsmentioning

confidence: 99%

Fructan to nitrogen ratio as an indicator of nutrient stress in wheat crops

McGRATH¹,

BLAKENEY²,

Batten³

1997

New Phytologist

View full text Add to dashboard Cite

show abstract

“…The DNS reagent consisted of 10 g of 3,5-dinitrosalicylic acid dissolved in 1 litre of solution containing 300 g Na-K tartarate and 16 g NaOH. The fructose content of the digests was determined by the thiobarbituric acid method (10) . The weight of food in the chewed samples was determined by measuring available carbohydrate in the exact amount of food in the non-chewed homogenised samples.…”

Section: Measuring Glucose Equivalents Released During In Vitro Digesmentioning

confidence: 99%

Baselines representing blood glucose clearance improve in vitro prediction of the glycaemic impact of customarily consumed food quantities

2009

View full text Add to dashboard Cite

Glycaemic responses to foods reflect the balance between glucose loading into, and its clearance from, the blood. Current in vitro methods for glycaemic analysis do not take into account the key role of glucose disposal. The present study aimed to develop a food intake-sensitive method for measuring the glycaemic impact of food quantities usually consumed, as the difference between release of glucose equivalents (GGE) from food during in vitro digestion and a corresponding estimate of clearance of them from the blood. Five foods -white bread, fruit bread, muesli bar, mashed potato and chickpeas -were consumed on three occasions by twenty volunteers to provide blood glucose response (BGR) curves. GGE release during in vitro digestion of the foods was also plotted. Glucose disposal rates estimated from downward slopes of the BGR curves allowed GGE dose-dependent cumulative glucose disposal to be calculated. By subtracting cumulative glucose disposal from cumulative in vitro GGE release, accuracy in predicting the in vivo glycaemic effect from in vitro GGE values was greatly improved.). Furthermore, the difference between the curves of cumulative GGE release and disposal closely mimicked in vivo incremental BGR curves. We conclude that valid measurement of the glycaemic impact of foods may be obtained in vitro, and expressed as grams of glucose equivalents per food quantity, by taking account not only of GGE release from food during in vitro digestion, but also of blood glucose clearance in response to the food quantity. Carbohydrate: Glycaemic impact: Glucose disposal: In vitro digestionFor practical consumer and dietetic use in glycaemia management, food values are required which will '. . . communicate glycaemic response in grams per serving of food' (1) , and which should be measured using '. . . validated in vitro methodology that accurately mimics in vivo behaviour' (2) . Current in vitro digestion methods for predicting relative glycaemic responses to foods measure carbohydrate that is rapidly available (for example, Englyst et al. ), or the area under the glucose release curve relative to a reference (5) . However, they cannot provide accurate or robust predictions of relative responses to whole foods varying in quantity, or accurately mimic the in vivo glycaemic response, because they do not allow for the effects of homeostasis. They do not take into account the fact that glycaemic responses to foods are a net effect of the balance between blood glucose loading and blood glucose disposal (GD), which depends dynamically on the rates of both. Not allowing for blood GD, and its dependence on the amount and rate of blood glucose loading, may lead to large inaccuracies when using glycaemic impact values from experimental portions to gauge the effect of the very different and varying food quantities that are consumed in a community setting. For instance, customarily consumed food portions often have a much lower glycaemic impact than would be expected from a glycaemic load value calculated from the glycaemic in...

show abstract

“…The latexes were separated by centrifugation for 15 minutes at 15000 rpm. The concentration of surfactant in solution was determined by a colorimetric method based on the reaction between fructose and thiobarbituric acid [21]. Surfactant solutions were mixed with thiobarbituric acid (2,883 g.dm -3 solution), in the presence of HCl (aq.)…”

Section: Adsorption Isothermsmentioning

confidence: 99%

Interaction forces between particles stabilized by a hydrophobically modified inulin surfactant

Nestor

Esquena

Solans

et al. 2007

Journal of Colloid and Interface Science

View full text Add to dashboard Cite

The adsorption isotherm of a hydrophobically modified inulin (INUTEC SP1) on Polystyrene (PS) and Poly(methyl methacrylate) (PMMA) particles was determined. The results show a high affinity isotherm for both particles as expected for a polymeric surfactant adsorption. The interactions forces between two layers of the hydrophobically modified inulin surfactant adsorbed onto a glass sphere and plate was determined using a modified atomic force microscope (AFM) apparatus. In the absence of any polymer, the interaction was attractive although the energy of interaction was lower than predicted by the van der Waals forces. The results between two layers of the adsorbed polymer confirms the adsorption isotherms results and provides an explanation to the high stability of the particles covered by INUTEC SP1 at high electrolyte concentration. Stability of dispersions against strong flocculation could be attributed to the conformation of the polymeric surfactant at the solid/liquid interface (multipoint attachment with several loops) which remains efficient at Na 2 SO 4 concentration reaching 1.5 mol.dm -3 . The thickness of the adsorbed polymer layer in water determined both by AFM and rheology measurements, was found to be about 9 nm.3

show abstract

A simple colorimetric method for the determination of sugars in fruit and vegetables

Cited by 211 publications

References 8 publications

Fructan to nitrogen ratio as an indicator of nutrient stress in wheat crops

Fructan to nitrogen ratio as an indicator of nutrient stress in wheat crops

Baselines representing blood glucose clearance improve in vitro prediction of the glycaemic impact of customarily consumed food quantities

Interaction forces between particles stabilized by a hydrophobically modified inulin surfactant

Contact Info

Product

Resources

About