Apparent molar volumes and <sup>1</sup>H‐NMR relaxation values of glucose syrups

Birch, G. G.; Karim, Roselina

doi:10.1002/jsfa.2740580416

Cited by 13 publications

(4 citation statements)

References 15 publications

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“…Furthermore, the lack of change in the relaxation measurements postharvest cannot be attributed to compounds present in the juice itself. The observation that shorter relaxation times are associated with increasing SSC in juices, or with increasing concentration in binary aqueous solutions, is consistent with the Carver and Richards (1972) formulation, in which is inversely related to the con-T 2 centration of exchangeable solute protons, and experimental results relating relaxation and carbohydrate concentration (Mora-Gutierrez and Baianu 1989 ;Birch and Karim 1992). Failure to obtain these results via the imaging process indicates that other factors must be involved.…”

Section: Discussionsupporting

confidence: 78%

Quantitative nmr imaging of kiwifruit (actinidia deliciosa) during growth and ripening

Clark¹,

Drummond

MacFall

1998

J. Sci. Food Agric.

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Quantitative 1H magnetic resonance (MR) imaging was used to determine relaxation changes (T1, T2‐CPMG) at regular intervals during growth and ripening of kiwifruit (Actinidia deliciosa var deliciosa). Temporal trends and differences between flesh, locule and core tissue were found for both relaxation parameters. However, no consistent associations were found between non‐destructive measurements and those for individual free sugars, soluble solids content (SSC) and macronutrients and micronutrients determined on dissected companion samples. Increases of 200% in total free sugar concentration in flesh and 68% in SSC accompanied starch hydrolysis after harvest. Despite the magnitude of these changes, relaxation times remained unaltered. These observations were repeated in a second investigation using A arguta fruit and T1, T2, T2‐CPMG and self‐diffusion image contrasts. Here, SSC increased 125% during a compressed 15‐day ripening period, while MR parameters like self‐diffusion declined only 7–14% from harvest values. T2‐CPMG relaxation was also investigated in aqueous solutions containing individual organic acids, sugars or pectate and juice from ripening fruit (4·7–15·5% SSC). Analysis of solutions and juices showed relaxation is indeed sensitive to increases in sugar composition but relatively insensitive to changes in organic acids and soluble pectin at concentrations normally found in fruit. Results imply that relaxation parameters determined from MR images may not be appreciably influenced by processes that cause solution composition to vary dramatically, even though these changes are reflected in the relaxation properties of the juice itself. Possible reasons for this are discussed with regard to the impact of cell structure and magnetic field strength on relaxation processes. © 1998 Society of Chemical Industry.

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Section: Discussionsupporting

confidence: 78%

Quantitative nmr imaging of kiwifruit (actinidia deliciosa) during growth and ripening

Clark¹,

Drummond

MacFall

1998

J. Sci. Food Agric.

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“…They suspect that this is the result of increased rotational correlation times due to more frequent interactions with the sugar molecules. Birch and Karim (1992) also saw a decrease in CPMG-T 2 with increasing glucose concentration and an increase in CPMG-T 2 with dextrose equivalent. This work also supports the conclusion that increased correlation times due to increased sugar content and degree of polymerization (100/DE) reduced CPMG-T 2 values.…”

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confidence: 79%

Evaluation of Low Field (5.40-MHz) Proton Magnetic Resonance Measurements of Dw and T2 as Methods of Nondestructive Quality Evaluation of Apples

Keener¹,

Stroshine²,

Nyenhuis³

1999

jashs

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A 5.40-MHz NMR system was used for measuring the self-diffusion coefficient of water (Dw) and the spin-spin relaxation constant (T2) in apple (Malus ×domestica Borkh.) tissue. The pulsed field gradient spin echo (PFGSE) technique was used to measure Dw, and the Carr-Purcell-Meiboom-Gill (CPMG) technique was used to measure T2. T2 and Dw values were compared for apples with differing amounts of soluble solids concentration (SSC) and with and without internal defects, such as bruising, watercore, and internal browning. `Granny Smith', `Golden Delicious', and `Delicious' apples were tested. In `Golden Delicious', Dw highly correlated with apple tissue SSC (P < 0.002, r2 = 0.68). This indicates that Dw could potentially be used for sorting `Golden Delicious” apples based on SSC, but the coefficient of determination needs to be improved before it would be commercially viable. There were no measurable differences in Dw among healthy apple tissue and tissue affected by either watercore or internal browning. T2 values showed no relationship between healthy apple tissue and bruised tissue in `Golden Delicious' and `Granny Smith'. However, in `Delicious' tissue, T2 values were statistically different between healthy and bruised tissue (P < 0.02). Further comparisons in `Delicious' between watercore and healthy apple tissue showed no differences. But, there were statistical differences found between T2 in healthy apple tissue and tissue with internal browning (P < 0.01). These results indicate that T2 could potentially be used for separating `Delicious' apples with internal browning or with bruising from healthy apples. Titratable acids and pH were correlated for `Golden Delicious' (P < 0.08). This correlation is significant because one may be able to noninvasively measure pH in `Golden Delicious' apples using NMR, which could then be correlated to titratable acids.

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“…The OH groups of glucose in the equatorial configuration fit within the quasi-tetrahedral arrangement of water molecules in the liquid state (Tait et a1 1972). Solutions with greater degrees of order may be expected to exchange energy more easily by proton-proton spin relaxation (Birch and Karim 1992). As a result, binding of water to glucose is stronger, causing T2 values to be shorter in glucose solution than in other mono/disaccharides solutions at the same concentration.…”

Section: Solution Propertiesmentioning

confidence: 99%

Sweet taste and solution properties of α,α‐trehalose

Portmann

Birch

1995

J Sci Food Agric

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a,a-Trehalose, a naturally occurring non-reducing disaccharide (apglucopyranosyl 1-1 a-D-ghcopyranoside) is investigated by solution parameters and sensorial effects. Interactions between aptrehalose and water give rise to hydration effects which are measurable by intrinsic viscosity [ q ] , apparent specific volume VO, , and NMR relaxation times. Water-solute interactions are prime determinants of taste qualities. An interpretation of sweetness intensity and persistence of a,a-trehalose is therefore offered, based on its solution properties and its effect on water structure. From the results, it appears that a,a-trehalose undergoes a better packing among water molecules than other sugars. a,aTrehalose is found to be less sweet but more persistent than sucrose, fructose, glucose or maltose.

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Apparent molar volumes and ¹H‐NMR relaxation values of glucose syrups

Cited by 13 publications

References 15 publications

Quantitative nmr imaging of kiwifruit (actinidia deliciosa) during growth and ripening

Quantitative nmr imaging of kiwifruit (actinidia deliciosa) during growth and ripening

Evaluation of Low Field (5.40-MHz) Proton Magnetic Resonance Measurements of Dw and T2 as Methods of Nondestructive Quality Evaluation of Apples

Sweet taste and solution properties of α,α‐trehalose

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Apparent molar volumes and 1H‐NMR relaxation values of glucose syrups

Cited by 13 publications

References 15 publications

Quantitative nmr imaging of kiwifruit (actinidia deliciosa) during growth and ripening

Quantitative nmr imaging of kiwifruit (actinidia deliciosa) during growth and ripening

Evaluation of Low Field (5.40-MHz) Proton Magnetic Resonance Measurements of Dw and T2 as Methods of Nondestructive Quality Evaluation of Apples

Sweet taste and solution properties of α,α‐trehalose

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Product

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About

Apparent molar volumes and ¹H‐NMR relaxation values of glucose syrups