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John N. Coupland - One of the best experts on this subject based on the ideXlab platform.
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Effect of surface-active stabilizers on the surface properties of Coconut Milk emulsions.
Food Hydrocolloids, 2009Co-Authors: Nattapol Tangsuphoom, John N. CouplandAbstract:Abstract Recently we have shown how surface-active stabilizers (≤1 wt% sodium dodecyl sulfate, polyoxyethylene sorbitan monolaurate, whey protein isolate, and sodium caseinate) added either before or after homogenization affect the stability and properties of Coconut Milk emulsions [Tangsuphoom, N., & Coupland, J. N. (2008). Effect of surface-active stabilizers on the microstructure and stability of Coconut Milk emulsions. Food Hydrocolloids , 22 (7), 1233–1242]. In this work, we propose a mechanism to explain these observations based on changes in surface composition and properties. Coconut Milk has a high surface protein load (∼7 mg m −2 ), of which the major component is cocosin. Small-molecule surfactants (>0.25%) added to the homogenized Coconut Milk displaced the Coconut proteins from the surface resulting in a change in ζ-potential. Dairy proteins added to the Coconut Milk after homogenization did not accumulate at the droplet surface. Addition of small-molecule surfactants to the Coconut Milk prior to homogenization completely displaced Coconut proteins from the oil–water interface. Homogenization of Coconut Milk with proteins resulted in a decrease in total protein surface concentration (to about 2 mg m −2 ) and a significant replacement of Coconut proteins by the dairy proteins. The change in ζ-potential also reflected the change in protein and surface composition as the values moved close to the value of Coconut oil emulsions stabilized solely with the corresponding added stabilizer.
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Effect of thermal treatments on the properties of Coconut Milk emulsions prepared with surface-active stabilizers
Food Hydrocolloids, 2009Co-Authors: Nattapol Tangsuphoom, John N. CouplandAbstract:Previously we have demonstrated improved stability of Coconut Milk emulsions homogenized with various surface-active stabilizers, i.e., 1 wt% sodium caseinate, whey protein isolate (WPI), sodium dodecyl sulfate (SDS), or polyoxyethylene sorbitan monolaurate (Tween 20) [Tangsuphoom, N., & Coupland, J. N. (2008). Effect of surface-active stabilizers on the microstructure and stability of Coconut Milk emulsions. Food Hydrocolloids, 22(7), 1233–1242]. This study examines the changes in bulk and microstructural properties of those emulsions following thermal treatments normally used to preserve Coconut Milk products (i.e., � 20 � C, � 10 � C, 5 � C, 70 � C, 90 � C, and 120 � C). Calorimetric methods were used to determine the destabilization of emulsions and the denaturation of Coconut and surface-active proteins. Homogenized Coconut Milk prepared without additives was destabilized by freeze–thaw, (� 20 � C and � 10 � C) but not by chilling (5
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Effect of pH and ionic strength on the physicochemical properties of Coconut Milk emulsions.
Journal of food science, 2008Co-Authors: Nattapol Tangsuphoom, John N. CouplandAbstract:Coconut Milk (16% to 17% fat, 1.8% to 2% protein) was extracted from Coconut (Cocos nucifera L.) endosperm and diluted in buffer to produce natural oil-in-water emulsions (10 wt% oil). The effect of pH (3 to 7) and NaCl (0 to 200 mM) on the properties and stability, namely, mean particle size, zeta-potential, viscosity, microstructure, and creaming stability, of the natural Coconut Milk emulsions was investigated. At pH values close to the isoelectric point (IEP) of the Coconut proteins (pH 3.5 to 4) and in the absence of NaCl, Coconut Milk flocculated, but did not coalesce. Flocculation corresponded to low surface charges and was accompanied by an increase in emulsion viscosity. Adding up to 200 mM NaCl to those flocculated emulsions did not change the apparent degree of flocculation. Coconut Milk emulsion at pH 6 was negatively charged and not flocculated. Upon addition of salt, the zeta-potential decreased from -16 to -6 mV (at 200 mM NaCl) but this was not sufficient to induce flocculation in Coconut Milk emulsions. At low pH (< IEP), the positively charged droplets of Coconut Milk emulsions only flocculated when the NaCI concentration exceeded 50 mM, as the zeta-potential approached zero.
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Effect of surface-active stabilizers on the microstructure and stability of Coconut Milk emulsions
Food Hydrocolloids, 2008Co-Authors: Nattapol Tangsuphoom, John N. CouplandAbstract:Abstract The effect of homogenization and surface-active stabilizers (0–1 wt% sodium caseinate, whey protein isolate, sodium dodecyl sulfate, or polyoxyethylene sorbitan monolaurate) on the microstructure and colloidal stability of Coconut Milk was determined using measurements of particle size and creaming, as well as microscopy. The freshly prepared Coconut Milk emulsions (1.8–2% protein, 17–18% fat) had large (d43∼10 μm) but non-flocculated droplets. Homogenization reduced the primary droplet size but induced flocculation. Adding small-molecule surfactants after the homogenization step can displace Coconut proteins from the interface and break up these flocs, but adding them before homogenization increased the efficiency of the homogenization step and produced stable, submicron-sized emulsion droplets. Adding protein stabilizers did not break up the flocs of Coconut Milk droplets when added after homogenization, but did increase the efficacy of the homogenization step when added prior to it. Adding stabilizers to non-homogenized Coconut Milk had no effect on the structure or properties of the emulsions.
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Effect of Heating and Homogenization on the Stability of Coconut Milk Emulsions
Journal of Food Science, 2005Co-Authors: Nattapol Tangsuphoom, John N. CouplandAbstract:The effects of homogenization and heat treatment on the colloidal stability of Coconut Milk were studied. Fresh Coconut Milk (15% to 17% fat, 1.5% to 2% protein) was extracted and stored at 30 °C before homogenization at 40/4 MPa (stage I/stage II). Both homogenized and non-homogenized samples were heated at 50 °C, 60 °C, 70 °C, 80 °C, and 90 °C for 1 h. Homogenization reduced the size of the primary emulsion droplets from 10.9 to 3.0 μm, but increased the degree of flocculation, presumably via a bridging mechanism. This flocculation was also responsible for increased viscosity of the homogenized samples. Heating increased the degree of flocculation in both non-homogenized and homogenized samples. A slight amount of coalescence was also observed after heating above 80 °C. All samples creamed after 24 h of storage, but the heated samples formed a larger cream layer, presumably because the flocculated droplets packed together less efficiently. Optical microscopy was used to confirm the combination of flocculation and creaming responsible for changes in Coconut Milk quality. The information obtained from this study provides a better understanding of the emulsion science important in controlling Coconut Milk functionality.
Nattapol Tangsuphoom - One of the best experts on this subject based on the ideXlab platform.
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Effect of surface-active stabilizers on the surface properties of Coconut Milk emulsions.
Food Hydrocolloids, 2009Co-Authors: Nattapol Tangsuphoom, John N. CouplandAbstract:Abstract Recently we have shown how surface-active stabilizers (≤1 wt% sodium dodecyl sulfate, polyoxyethylene sorbitan monolaurate, whey protein isolate, and sodium caseinate) added either before or after homogenization affect the stability and properties of Coconut Milk emulsions [Tangsuphoom, N., & Coupland, J. N. (2008). Effect of surface-active stabilizers on the microstructure and stability of Coconut Milk emulsions. Food Hydrocolloids , 22 (7), 1233–1242]. In this work, we propose a mechanism to explain these observations based on changes in surface composition and properties. Coconut Milk has a high surface protein load (∼7 mg m −2 ), of which the major component is cocosin. Small-molecule surfactants (>0.25%) added to the homogenized Coconut Milk displaced the Coconut proteins from the surface resulting in a change in ζ-potential. Dairy proteins added to the Coconut Milk after homogenization did not accumulate at the droplet surface. Addition of small-molecule surfactants to the Coconut Milk prior to homogenization completely displaced Coconut proteins from the oil–water interface. Homogenization of Coconut Milk with proteins resulted in a decrease in total protein surface concentration (to about 2 mg m −2 ) and a significant replacement of Coconut proteins by the dairy proteins. The change in ζ-potential also reflected the change in protein and surface composition as the values moved close to the value of Coconut oil emulsions stabilized solely with the corresponding added stabilizer.
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Effect of thermal treatments on the properties of Coconut Milk emulsions prepared with surface-active stabilizers
Food Hydrocolloids, 2009Co-Authors: Nattapol Tangsuphoom, John N. CouplandAbstract:Previously we have demonstrated improved stability of Coconut Milk emulsions homogenized with various surface-active stabilizers, i.e., 1 wt% sodium caseinate, whey protein isolate (WPI), sodium dodecyl sulfate (SDS), or polyoxyethylene sorbitan monolaurate (Tween 20) [Tangsuphoom, N., & Coupland, J. N. (2008). Effect of surface-active stabilizers on the microstructure and stability of Coconut Milk emulsions. Food Hydrocolloids, 22(7), 1233–1242]. This study examines the changes in bulk and microstructural properties of those emulsions following thermal treatments normally used to preserve Coconut Milk products (i.e., � 20 � C, � 10 � C, 5 � C, 70 � C, 90 � C, and 120 � C). Calorimetric methods were used to determine the destabilization of emulsions and the denaturation of Coconut and surface-active proteins. Homogenized Coconut Milk prepared without additives was destabilized by freeze–thaw, (� 20 � C and � 10 � C) but not by chilling (5
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Effect of pH and ionic strength on the physicochemical properties of Coconut Milk emulsions.
Journal of food science, 2008Co-Authors: Nattapol Tangsuphoom, John N. CouplandAbstract:Coconut Milk (16% to 17% fat, 1.8% to 2% protein) was extracted from Coconut (Cocos nucifera L.) endosperm and diluted in buffer to produce natural oil-in-water emulsions (10 wt% oil). The effect of pH (3 to 7) and NaCl (0 to 200 mM) on the properties and stability, namely, mean particle size, zeta-potential, viscosity, microstructure, and creaming stability, of the natural Coconut Milk emulsions was investigated. At pH values close to the isoelectric point (IEP) of the Coconut proteins (pH 3.5 to 4) and in the absence of NaCl, Coconut Milk flocculated, but did not coalesce. Flocculation corresponded to low surface charges and was accompanied by an increase in emulsion viscosity. Adding up to 200 mM NaCl to those flocculated emulsions did not change the apparent degree of flocculation. Coconut Milk emulsion at pH 6 was negatively charged and not flocculated. Upon addition of salt, the zeta-potential decreased from -16 to -6 mV (at 200 mM NaCl) but this was not sufficient to induce flocculation in Coconut Milk emulsions. At low pH (< IEP), the positively charged droplets of Coconut Milk emulsions only flocculated when the NaCI concentration exceeded 50 mM, as the zeta-potential approached zero.
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Effect of surface-active stabilizers on the microstructure and stability of Coconut Milk emulsions
Food Hydrocolloids, 2008Co-Authors: Nattapol Tangsuphoom, John N. CouplandAbstract:Abstract The effect of homogenization and surface-active stabilizers (0–1 wt% sodium caseinate, whey protein isolate, sodium dodecyl sulfate, or polyoxyethylene sorbitan monolaurate) on the microstructure and colloidal stability of Coconut Milk was determined using measurements of particle size and creaming, as well as microscopy. The freshly prepared Coconut Milk emulsions (1.8–2% protein, 17–18% fat) had large (d43∼10 μm) but non-flocculated droplets. Homogenization reduced the primary droplet size but induced flocculation. Adding small-molecule surfactants after the homogenization step can displace Coconut proteins from the interface and break up these flocs, but adding them before homogenization increased the efficiency of the homogenization step and produced stable, submicron-sized emulsion droplets. Adding protein stabilizers did not break up the flocs of Coconut Milk droplets when added after homogenization, but did increase the efficacy of the homogenization step when added prior to it. Adding stabilizers to non-homogenized Coconut Milk had no effect on the structure or properties of the emulsions.
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Effect of Heating and Homogenization on the Stability of Coconut Milk Emulsions
Journal of Food Science, 2005Co-Authors: Nattapol Tangsuphoom, John N. CouplandAbstract:The effects of homogenization and heat treatment on the colloidal stability of Coconut Milk were studied. Fresh Coconut Milk (15% to 17% fat, 1.5% to 2% protein) was extracted and stored at 30 °C before homogenization at 40/4 MPa (stage I/stage II). Both homogenized and non-homogenized samples were heated at 50 °C, 60 °C, 70 °C, 80 °C, and 90 °C for 1 h. Homogenization reduced the size of the primary emulsion droplets from 10.9 to 3.0 μm, but increased the degree of flocculation, presumably via a bridging mechanism. This flocculation was also responsible for increased viscosity of the homogenized samples. Heating increased the degree of flocculation in both non-homogenized and homogenized samples. A slight amount of coalescence was also observed after heating above 80 °C. All samples creamed after 24 h of storage, but the heated samples formed a larger cream layer, presumably because the flocculated droplets packed together less efficiently. Optical microscopy was used to confirm the combination of flocculation and creaming responsible for changes in Coconut Milk quality. The information obtained from this study provides a better understanding of the emulsion science important in controlling Coconut Milk functionality.
Yong-huan Yun - One of the best experts on this subject based on the ideXlab platform.
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Effect of sterilization and storage on volatile compounds, sensory properties and physicochemical properties of Coconut Milk
Microchemical Journal, 2020Co-Authors: Wenzhu Wang, Haiming Chen, Wenxue Chen, Qiuping Zhong, Weijun Chen, Yong-huan YunAbstract:Abstract Sterilization is an important process in beverage production that not only guarantees the edible safety of beverage but also extends its shelf life. However, the quality changes in the Coconut Milk sterilization and storage has received scarce attention in regard to beverages. Therefore, this study was conducted to investigate the effect of sterilization (at 121 ℃ for 30 min.) and storage (from day 1 to day 19) on the quality of Coconut Milk. The volatile compounds present in Coconut Milk were determined by solid-phase microextraction and gas chromatography-mass spectrometry. A total of 31 volatile compounds in Coconut Milk were tentatively identified, including lactones (34.4%), esters (31.5%), aldehydes (20.0%), acids (3.8%), ketones (2.3%), alcohols (1.4%) and other (0.6%). The relative content of delta-octalactone in lactones had no significant change after sterilization compared with nontreatment, while an increase was observed in the relative content of delta-octalactone from 18.14% to 23.81% in storage. In addition, although the percentage of ethyl octanoate (from 13.15% to 9.05%) in esters significantly decreased after sterilization compared with nontreatment, the content had no significant alter during storage. Those results showed that the volatile compounds in Coconut Milk changed after sterilization and storage. Further analysis with descriptive sensory evaluation showed that the sensory evaluation ranged from the moderate to extreme levels according to the evaluators. This result indicated that no remarkable change in the sensory qualities of Coconut Milk by sterilizing and storing. Meanwhile, all attributes had a positive effect on Coconut Milk, such as overall Coconut Milk flavor, sweet, nutty. There is no conspicuous affect in the acceptability of Coconut Milk by evaluators. Overall, these results indicate that sterilization had no significant affect the flavor of Coconut Milk; moreover, appropriate storage can improve the acceptability of Coconut Milk before product shipment.
Thepkunya Harnsilawat - One of the best experts on this subject based on the ideXlab platform.
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Effect of sucrose ester and carboxymethyl cellulose on physical properties of Coconut Milk
Journal of Food Science and Technology, 2019Co-Authors: Narisara Thanatrungrueang, Thepkunya HarnsilawatAbstract:The influence of sucrose ester (SE) and carboxymethyl cellulose (CMC) on the physical properties of Coconut Milk was determined using response surface methodology based on central composite design. The R ^2 of all response variables was more than 0.80 which indicated a high proportion of variability was explained by the model and showed that increasing the amount of SE decreased the droplet size of Coconut Milk. The viscosity and creaming index were dependent on the SE and CMC concentration. Increasing the SE and CMC concentration increased viscosity but creaming index was decreased. The results suggested that suitable amount of SE and CMC should be specified in order to obtain a high quality of Coconut Milk products.
Pasawadee Pradipasena - One of the best experts on this subject based on the ideXlab platform.
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Interfacial and emulsifying properties of sucrose ester in Coconut Milk emulsions in comparison with Tween
Food Hydrocolloids, 2013Co-Authors: Suwimon Ariyaprakai, Tanachote Limpachoti, Pasawadee PradipasenaAbstract:Abstract In this study, sucrose esters were presented as a promising alternative to petrochemically synthesized Tweens for application in Coconut Milk emulsions. The interfacial and emulsifier properties of sucrose ester (SE), mainly sucrose monostearate, had been investigated in comparison with Tween 60 (TW), an ethoxylate surfactant. The interfacial tension measurement showed that SE had a slightly better ability to lower the interfacial tension at Coconut oil–water interface. These surfactants (0.25 wt%) were applied in Coconut Milk emulsions with 5 wt% fat content. The effects of changes in pH, salt concentration, and temperature on emulsion stability were analyzed from visual appearance, optical micrograph, droplet charges, particle size distributions, and creaming index. Oil droplets in both SE and TW Coconut Milk emulsions extensively flocculated at pH 4, or around the pI of the Coconut proteins. Salt addition induced flocculation in both emulsions. The pH and salt dependence indicated polyelectrolyte nature of proteins, suggesting that the proteins on the surface of oil droplets were not completely displaced by either added nonionic SE or TW. TW Coconut Milk emulsions appeared to be thermally unstable with some coalesced oil drops after heating and some oil layers separated on top after freeze thawing. The change in temperature had much lesser influence on stability of SE Coconut Milk emulsions and, especially, it was found that SE emulsions were remarkably stable after the freeze thawing.