Prediction of optimal conditions of infrared assisted freeze-drying of aloe vera (Aloe barbadensis) using response surface methodology

Chakraborty, Rajat; Bera, M.; Mukhopadhyay, P.; Bhattacharya, Pratik

doi:10.1016/j.seppur.2011.05.023

Cited by 43 publications

(20 citation statements)

References 31 publications

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“…Ten random areas were measured through the plastic pockets and mean values were reported for each sample. Using this method, CIELAB coordinates show the degree of brightness (L), the degree of redness (+a) or greenness (-a), and the degree of yellowness (+b) or blueness (-b) (Coultate, 2002;Chakrborty et al, 2011).…”

Section: Methodsmentioning

confidence: 99%

Effects of Energy and Macronutrient Intake on Cognitive Function Through the Lifespan

Gibson¹

2013

Proceedings of the Latvian Academy of Sciences. Section B. Natural, Exact, and Applied Sciences

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INTRODUCTIONThis review will briefly consider the impact on cognitive development and function, of variation in intake (insufficient or excessive) of the macronutrients, protein, carbohydrate and fat, and, where its effects can be separated, energy, over the human lifespan. For each macronutrient, attention will be paid to what is known about the role of specific forms for cognition and brain function. This review is mainly concerned with evidence in human beings, and emphasis is placed on highlighting current understanding of the evidence, rather than an extensive review of the literature.All the macronutrients can provide energy, albeit with differing priorities and target organs, as well as carbon for structural functions, and many forms are fundamental to cellular processes governing growth, signalling and survival (Mann and Truswell, 2012). For the brain specifically, carbohydrates provide glucose as the primary energy source, amino acids in proteins provide the precursors for synthesis of neurotransmitters and create their receptors, while fatty acids provide the structural basis of neuronal cell membranes. These properties point to ways in which macronutrient intake may be crucial for optimal brain function.Firstly, the importance of adequate intake of energy and protein, both for the pregnant mother and thus the intrauterine nutritional environment for the foetus, and for the neonate and infant child, will be considered. Breastfeeding will briefly be compared to formula feeding, as the quantity and quality of fats and protein may have implications for cognitive development.Next, the review will discuss evidence for the benefits of breakfast, and other meal types, for cognitive function in school children, adolescents and adults, comparing effects of different forms of breakfast, including the nature of the carbohydrates and the glycaemic index of the meal. For adolescents and adults, there is extensive literature on the effects of glucose loads on cognition, particularly memory and attention: this literature will be summarised, and the strengths and weaknesses of the evidence, and its implications, discussed.PROCEEDINGS OF THE LATVIAN ACADEMY OF SCIENCES. Section B, Vol. 67 (2013), No. 4/5 (685/686), pp. 303-314. DOI: 10.2478/prolas-2013 EFFECTS OF ENERGY AND MACRONUTRIENT INTAKE ON COGNITIVE FUNCTION THROUGH THE LIFESPAN Edward Leigh GibsonDepartment of Psychology, University of Roehampton, London, UK l.gibson@roehampton.ac.uk Communicated by Valdis PîrâgsThis paper reviews effects of both insufficient and excessive energy and macronutrient intake on cognition over the lifespan, including the prenatal period, infancy, childhood, and adulthood. In the brain, the hippocampus is particularly vulnerable to both protein malnutrition and energy undernutrition in utero or infancy, resulting in impaired neurogenesis and deficits in memory and spatial learning, reduced anxiety and increased impulsivity, reflected in impairments of neurotransmitter systems. Conversely, higher protein intake is associated with i...

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Section: Methodsmentioning

confidence: 99%

Effects of Energy and Macronutrient Intake on Cognitive Function Through the Lifespan

Gibson¹

2013

Proceedings of the Latvian Academy of Sciences. Section B. Natural, Exact, and Applied Sciences

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“…The sample, with initial moisture content of 90.70% (wet basis), was placed in a screw-capped 5 mL glass vial and was frozen through conventional refrigeration by keeping it inside a deep freezer (Blue Star, India; model C8F320) maintained at À20 AE 0.1 C for 12 h to attain the desired temperature of À15 AE 1 C. [19] Experimental Set-Up…”

Section: Pre-freezingmentioning

confidence: 99%

Intensification of Freeze-Drying Rate ofBacillus subtilisMTCC 2396 Using Tungsten Halogen Radiation: Optimization of Moisture Content and α-Amylase Activity

2014

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A novel freeze-drying protocol has been explored to render fast and cost-effective freeze drying of hyperamylase producing Bacillus subtilis MTCC2396 employing a tungsten halogen lamp radiator (THLR) as a heat source. Response surface methodology assessed the maximum reduction in moisture content (96.07%) and minimum reduction in a-amylase (EC 3.2.1.1) activity (1.02%) in 4 h drying time at 42.5 C radiation temperature. a-amylase activity (0.046 U) and final moisture content (3.93%) of the optimally freeze-dried bacterial strain appeared satisfactory. The freeze-drying time using THLR (4 h) is remarkably lower compared to that under a conventional conductive plate heater (CPH) (10 h) at otherwise identical conditions. The higher effective moisture diffusivity of 0.0052 to 0.0078 m 2 /s under THLR compared to 0.00084 to 0.0015 m 2 /s under CPH (corresponding to 20-50 C) advocated the superiority of the THLR heating protocol. The higher efficacy of THLR was also evidenced through lower activation energy (8.42 kJ/mol) of moisture diffusion compared to that (12.051 kJ/mol) of CPH. The optimally freeze-dried bacteria demonstrated the same growth rate in addition to exhibiting excellent retention of bioremedial (Hg 2þ removal) activity to that of the control.

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“…Moreover, the freeze-drying method has been extensively used in the pharmaceutical and food industries to obtain dehydrated materials that are easily degraded (10). Freeze-drying is often used because the process enables the retention of the physical and chemical properties of the products, such as the color, the vitamins, the antioxidant contents and other sensorial properties, including the original aroma and flavor.…”

Section: Introductionmentioning

confidence: 99%

“…Freeze-drying is often used because the process enables the retention of the physical and chemical properties of the products, such as the color, the vitamins, the antioxidant contents and other sensorial properties, including the original aroma and flavor. Here, freeze-drying was used for the dehydration of fresh Aloe vera foams (10,11).…”

Section: Introductionmentioning

confidence: 99%

Physical characterization of freeze-dried foam prepared from aloe vera gel and guar gum

Santacruz-Vázquez

Cortés

2015

Vitae

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Background: Foams are colloidal dispersions of a gas suspended in a dispersing phase, which consisting of a semi-freeze-dried or viscous liquid phase. The physical properties of food foams are the result of the bubble characteristics and their spatial arrangement. Objectives: The aim of this work was to obtain foams of A. vera gel and guar gum and describe the changes in their physical properties and microstructure during freeze-drying using the fractal dimension concept and image analysis techniques. Methods: The porosity, density, and volume expansion factor of the fresh foams that were based on the A. vera foams were determined. The kinetics of foam texture, color, porosity and microstructure of the freeze-dried foams were obtained. The fractal texture dimension of surface (FD SDBC ) and microstructure (FD ESEM ) of the foams were determined as indicators of structural changes after freeze-drying. The guar gum concentrations used to obtain the A. vera prefoam were expressed in w/w as F1 (control sample without gum), F2 (2%), F3 (4%) and F4 (6%). Results: We obtained stable freeze-dried foams of Aloe vera gel and guar gum. The porosity, density and volume expansion factor of the fresh and freeze-dried foams were affected by the addition of the guar gum. Changes in the topology of the freeze-dried foam surface during the drying process resulted in a high rugosity compared with the original smooth surface. The microstructure of the dried foam samples suggested a relationship between the gum concentration of the prefoam A. vera gel mixture and the physical properties before and after freeze-drying, such as an increase in the microstructural alterations and surface roughness during freeze-drying. The roughness of the freeze-dried foam surface, described by the FD SDBC represented the macroscopic physical changes of the samples and correlated with the changes in the foam microstructure, which were described by the fractal dimension of the Environmental Scanning Electron Microscopy ESEM microphotographs (FD ESEM ). Conclusions: The digital analysis of the structure and porosity of the freeze-dried foam can be used to quantify the effect of gum concentrations on the morphological features and physical properties of foams during freeze-drying.

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Prediction of optimal conditions of infrared assisted freeze-drying of aloe vera (Aloe barbadensis) using response surface methodology

Cited by 43 publications

References 31 publications

Effects of Energy and Macronutrient Intake on Cognitive Function Through the Lifespan

Effects of Energy and Macronutrient Intake on Cognitive Function Through the Lifespan

Intensification of Freeze-Drying Rate ofBacillus subtilisMTCC 2396 Using Tungsten Halogen Radiation: Optimization of Moisture Content and α-Amylase Activity

Physical characterization of freeze-dried foam prepared from aloe vera gel and guar gum

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