Use of hydrocolloids as cryoprotectant for frozen foods.

Freezing is one of the widely used preservation methods to preserve the quality of food products but it also results in deteriorative changes in textural properties of food which in turn affects its marketability. Different foodstuffs undergo different types of changes in texture, taste and overall acceptability upon freezing and subsequent frozen storage. Freezing and thawing of pre-cut or whole fruits and vegetables causes many deleterious effects including texture and drip losses. The major problem in stability of ice-cream is re-crystallization phenomena which happens due to temperature fluctuations during storage and finally impairs the quality of ice-cream. Frozen storage for longer periods causes rubbery texture in meat and fish products. To overcome these problems, hydrocolloids which are polysaccharides of high molecular weight, are used in numerous food applications involving gelling, thickening, stabilizing, emulsifying etc. They could improve the rheological and textural characteristics of food systems by changing the viscosity. They play a major role in retaining texture of fruits and vegetables after freezing. They provide thermodynamic stability to ice cream to control the process of re-crystallization. Hydrocolloids find application in frozen surimi, minced fish, and meat products due to their water-binding ability. They are also added to frozen bakery products to improve shelf-stability by retaining sufficient moisture and retarding staling. Various hydrocolloids impart different cryoprotective effects to food products depending upon their solubility, water-holding capacity, rheological properties, and synergistic effect with other ingredients during freezing and frozen storage.

High pressure, temperature and time-dependent effects on enzymatic and microbial properties of fresh sugarcane juice.

Efficacy of variable high pressure, temperature and time on the browning causing enzymes and microbial activities, which are major spoilage factors during preservation of sugarcane juice, was studied. The juice was processed at 200-600 MPa pressure for 2-8 min at 40 and 60 °C and their effect on polyphenol oxidase and peroxidase as well as microbiological quality in terms of total plate count, yeast and molds and total coliforms was studied. Application of high pressures were found to cause significant decrease in enzymatic and microbial activities. The effects were found to be significantly more pronounced at 60 °C as compared to 40 °C. Process time also caused significant (p < 0.05) negative effect on microbial and enzyme activities. The sugarcane juice treated at 600 MPa for 6 min at 60 °C was found sufficient to inactivate the microbial counts completely. Whereas, enzymes were found to be completely inactivated in the samples processed at 600 MPa for 8 min at 60 °C. A pressure of 600 MPa at 60 °C for 8 min could be applied during commercial preservation of sugarcane juice for getting complete inactivation of browning causing enzymes and spoilage causing microorganisms.

Optimization and quality assessment of ready-to-eat intermediate moisture compressed beetroot bar.

A ready-to-eat food product in the form of compressed bar from beetroot, enriched with dates and oats was developed. Levels of intermediate moisture beetroot shreds (60-100 g), dates (10-30 g) and oats (5-15 g) were optimized using response surface methodology and its quality attributes were investigated over a period of 6 months at different temperature conditions (ambient temperature; 22-32 and 37 °C). Optimum formulation for best beetroot bar consisted of beetroot shreds, dates and oat were derived as 71.8, 21.2, and 8.4 g, respectively. Developed product was found rich in fibers and minerals and recorded 38.4 mg/100 g betacyanains, 23.1 mg/100 g betaxanthins, 295 mg/100 g total phenolics (TP) and 160 mg/100 g total flavonoids (TF). The shelf stability studies of bar revealed predominant changes in bioactive compounds was caused by storage temperature. A loss of around 30, 15, 25, 31 and 32 % was observed for betacyanins, betaxanthins, TP, TF and radical scavenging activity, respectively during storage of 6 months at 6 °C compared to AT or 37 °C temperature conditions. The product had high overall sensory acceptability as well as microbial safety up to 6 months when stored at AT. The study indicated that beetroot could be effectively utilized into a novel shelf-stable ready-to-eat nutritious compressed product.

Shelf life extension of green chillies (Capsicum annuum L.) using shellac-based surface coating in combination with modified atmosphere packaging.

Shellac-based surface coating was used in combination with passive modified atmosphere (MA) packaging for shelf life extension of fresh green chillies. The green chillies were coated with shellac coating, packed in anti-fog film and kept at 8 ± 1 °C for storage along with uncoated control. The coated and MA packed chillies showed significantly lower respiration rates as compared to control. The physico-chemical characteristics showed significantly lesser variations in terms of physiological loss in weight, firmness, colour, pigments, ascorbic acid and antioxidant activity during storage. A shelf life extension of 48 days was observed for coated and MA packed chillies against uncoated and MA packed (28 days) and control (15 days) ones. Shellac coated chillies showed a shelf life of 30 days at 8 ± 1 °C. Shellac coating along with the passive MA packaging resulted in restriction of metabolic activities (respiration) and delayed senescence and was found most effective in maintaining the postharvest quality of green chillies during low temperature storage.

Rheological behaviour of enzyme clarified sapota (Achras sapota L) juice at different concentration and temperatures.

Rheological behaviour of enzyme clarified sapota (Achras sapota L.) juice at different temperatures (10 to 85 °C) and total soluble solid content (10.2 to 55.6 °brix) corresponding to a water activity (aw) (0.986 to 0.865) was studied using controlled stress rheometer by coaxial cylinders attachment. The rheological parameter shear stress (Pa) was measured upto a shear rate of 1,000 s(-1). The investigation showed that the enzyme clarified sapota juice and its concentrates behaved like a Newtonian liquid and the viscosity (η) values were in the range 4.340 to 56.418 mPa s depending upon temperature and concentration studied. The temperature dependency of viscosity of enzyme clarified sapota juice was described by Arrhenius equation (r > 0.94) and activation energy (Ea) for viscous flow was in the range 5.218 to 25.439 KJ/mol depending upon concentration. The effect of total soluble solid content on flow activation energy was described by exponential relationship (r > 0.95, rmse% <13.5, p < 0.01) and that of water activity was described by power law relation (r > 0.99, rmse% <5.80, p < 0.01). The effect of total soluble solid content on viscosity of enzyme clarified sapota juice followed second order exponential type relationship (r > 0.99, rmse% < 3.53) at the temperature used. The effect of water activity on viscosity of enzyme clarified sapota juice followed power law equation (r > 0.98, rmse% < 4.38). A single equation representing combined effect of temperature and total soluble solid content/water activity on viscosity of enzyme clarified sapota was established.

Rheological characteristics of inulin solution at low concentrations: Effect of temperature and solid content.

The rheological properties of inulin solution was investigated at different solid content (Xs) ranging from 1 to 12 % at wide range of temperatures ranging from 10 to 85 °C. The rheological parameter shear stress was measured upto a shear rate of 300 s(-1) using concentric cylinders attachment by controlled stress rheometer. The investigation showed that the inulin solution behaved like Newtonian liquid and viscosity (η) was in the range 2.0998 to 3.2439 mPa s depending upon the concentration and temperature studied. The temperature dependency of Newtonian viscosity of inulin solution was described by Arrhenius equation (r > 0.88, p < 0.05) and activation energy (Ea) for viscous flow was in the range 2.111 to 3.013 kJ/mol depending upon the solid content studied. The flow activation energy (Ea) of inulin solution was significantly (p < 0.05) affected by solid content and described by exponential type equation (r = 0.9646, rmse% = 1.07, p < 0.001). Effect of solid content on Newtonian viscosity was described by linear as well as power law models depending upon the temperature studied. The combined effect of temperature and solid content on Newtonian viscosity of inulin solution was described by power law type equation and represented as η = 0.8835* (Xs)(0.0731) *Exp(296.410/T), (r = 0.9538, p < 0.001, rmse% = 0.15) Where η is Newtonian viscosity in mPa s, Xs is solid content in % and T is temperature in Kelvin (K).

Shellac and Aloe vera gel based surface coating for shelf life extension of tomatoes.

Shellac (S) and Aloe vera gel (AG) were used to develop edible surface coatings for shelf-life extension of tomato fruits. The coating was prepared by dissolving de-waxed and bleached shellac in an alkaline aqueous medium as such as well as in combination with AG. Incorporation of AG in shellac coating improved permeability characteristics of the coating film towards oxygen and carbon dioxide and water vapours. The coatings when applied to tomatoes delayed senescence which was characterized by restricted changes in respiration and ethylene synthesis rates during storage. Texture of the fruits when measured in terms of firmness showed restricted changes as compared to untreated control. Similar observations were also recorded in the case of instrumental colour (L*, a* and b* values). The developed coatings extended shelf-life of tomatoes by 10, 8 and 12 days in case of shellac (S), AG and composite coating (S + AG) coated fruits, respectively; when kept at ambient storage conditions (28 ± 2 °C).

Evaluation of sensory acceptability and storage stability of frozen carrot based dessert.

In the present study a recipe for frozen carrot based dessert (carrot halwa) was standardized on the basis of sensory characteristics such as appearance, odor, texture, taste and overall acceptability (OAA). The product was developed without addition of pure ghee to improve the storage stability under frozen conditions (-20 °C). Sensory properties of the developed product (OAA score = 8.60) were found to be equally good as compared to the conventional carrot halwa (OAA score = 8.75) which was prepared using pure ghee. From the physico-chemical analysis the developed product was found to have lower amount of fat (ca. 12%) than the conventional one. During the frozen storage, microbial growth in the product was found to be non-significant (P > 0.05). The free fatty acid content, peroxide value and thiobarbituric acid content increased during frozen storage of 15 months. But the increase was insignificant. Loss in total carotenoids content of the product was found to be 60.5% from initial value at the end of 15 months frozen storage.

Thermophysical properties of enzyme clarified Lime (Citrus aurantifolia L) juice at different moisture contents.

Thermophysical properties of enzyme clarified lime (Citrus aurantifolia L.) juice were evaluated at different moisture contents ranging from 30.37 % to 89.30 % (wet basis) corresponding to a water activity range of 0.835 to 0.979. The thermophysical properties evaluated were density, Newtonian viscosity, thermal conductivity, specific heat and thermal diffusivity. The investigation showed that density and Newtonian viscosity of enzyme clarified lime juice decreased significantly (p < 0.05) with increase in moisture content and water activity, whereas thermal conductivity and specific heat increased significantly (p < 0.05) with increase in moisture content and water activity and the thermal diffusivity increased marginally. Empirical mathematical models were established relating to thermophysical properties of enzyme clarified lime juice with moisture content/water activity employing regression analysis by the method of least square approximation. Results indicated the existence of strong correlation between thermophysical properties and moisture content/water activity of enzyme clarified lime juice, a significant (p < 0.0001) negative correlation between physical and thermal properties was observed.

Nisin based stabilization of novel fruit and vegetable functional juices containing bacterial cellulose at ambient temperature.

The current study reports the preparation and stabilization of novel functional drinks based on fruit and vegetable juices incorporating bacterial cellulose from Acetobacter xylinum. Pineapple, musk melon, carrot, tomato, beet root and a blend juice containing 20 % each of carrot and tomato juice with 60 % beet root juice has been studied. These juices have been stabilized over a storage period of 90 days at 28 °C, by the use of nisin and maintaining a low pH circumventing the need for any chemical preservatives or refrigeration. Instrumental color values have been correlated with the pigment concentrations present in the fresh as well as stored juices. There was 36, 72 and 60 % loss of total carotenoids in the case of carrot, pineapple and musk melon juices respectively while the lycopene content remained unchanged after 90 days of storage. The betanin content decreased 37 % in the case of beetroot juice and 25 % in the case of beetroot juice blended with carrot and tomato juices. Sensory analysis has revealed a clear preference for the beetroot blended mixed juice.

Kinetics of moisture loss and oil uptake during deep fat frying of Gethi (Dioscorea kamoonensis Kunth) strips.

Investigation was carried out to study kinetics of moisture loss, oil uptake and tristimulus colour during deep fat frying of Gethi (Dioscorea kamoonensis kunth) strips. Deep fat frying of Gethi strips of size 6 × 6 × 40 mm was carried out in a laboratory scale fryer at different temperatures ranging from 120 to 180 °C. The investigation showed that the moisture loss and oil uptake followed the first order kinetics equation (r > 0.95, p < 0.05). The kinetic coefficients for moisture loss and oil uptake increased significantly (p < 0.05) with temperature from 0.166 to 0.889 min(-1) and 0.139 to 0.430 min(-1) respectively. The temperature dependency of rate constants for moisture loss and oil uptake values was described using Arrhenius equation (r > 0.99, p < 0.01). The activation energies for moisture loss and oil uptake were found to be 41.53 KJ/mol and 27.12 KJ/mol respectively. The hunter colour parameters were significantly affected by frying temperature and frying time. The hunter lightness (L) value increased with respect to frying time initially, followed by decline and same trend was observed at higher temperatures of frying with elevated rate, whereas hunter redness (a) value increased significantly (p < 0.01) with time as well as temperature of frying and obeyed zero order rate equation. The temperature dependency kinetic coefficients of Hunter (a) value were described by Arrhenius equation and the energy of activation for change in hunter redness was found to be 42.41 KJ/mol (r > 0.99, p < 0.01). The other hunter colour parameters such as chroma, hue angle and total colour difference were markedly affected by frying temperature as well as frying time.

A refreshing beverage from mature coconut water blended with lemon juice.

Coconut water obtained from the mature coconuts was blended with lemon juice to develop a refreshing beverage. The levels of total soluble solids (°Brix) in the coconut beverage and lemon juice (%), were optimized using response surface methodology and considering pH, CIE L* value and sensory attributes (colour, aroma, taste, consistency and overall acceptability) as responses. A number total of 14 experiments were carried out following Central Composite Rotatable Design (CCRD) keeping 6 experiments at centre point. The data obtained were analyzed using multiple regression technique and the quadratic equations (R(2), 98.14-99.89 %) were found to fit well in describing the effect of variables on responses studied. An optimum condition for the coconut water beverage was obtained at 13.5°Brix blended with 2 % lemon juice. The mature coconut water beverage blended with lemon juice showed a shelf-life of 6 months in packed conditions at low (5 °C), ambient (25 ± 2 °C) and high (37 °C) temperatures on the basis of physicochemical, microbiological and sensory attributes.

Process optimization for osmo-dehydrated carambola (Averrhoa carambola L) slices and its storage studies.

An osmotic-dehydration process protocol for Carambola (Averrhoacarambola L.,), an exotic star shaped tropical fruit, was developed. The process was optimized using Response Surface Methodology (RSM) following Central Composite Rotatable Design (CCRD). The experimental variables selected for the optimization were soak solution concentration (°Brix), soaking temperature (°C) and soaking time (min) with 6 experiments at central point. The effect of process variables was studied on solid gain and water loss during osmotic dehydration process. The data obtained were analyzed employing multiple regression technique to generate suitable mathematical models. Quadratic models were found to fit well (R(2), 95.58 - 98.64 %) in describing the effect of variables on the responses studied. The optimized levels of the process variables were achieved at 70°Brix, 48 °C and 144 min for soak solution concentration, soaking temperature and soaking time, respectively. The predicted and experimental results at optimized levels of variables showed high correlation. The osmo-dehydrated product prepared at optimized conditions showed a shelf-life of 10, 8 and 6 months at 5 °C, ambient (30 ± 2 °C) and 37 °C, respectively.

Development of ready-to-fry frozen vegetable snack and its quality evaluation.

A formulation for the development of a crispy texture of crust in vegetable snack after freezing and frying was standardized using different flours such as whole-wheat flour (WWF), refined wheat flour (RWF), rice flour (RF) and semolina (S). Formulation with 60% WWF, 20% RWF, 10% RF and 10% S was selected based on sensory characteristics (overall acceptability >7.8). Incorporation of RF significantly (P < 0.05) changed the texture of the raw snack as indicated by texture profile analysis. Higher levels of rice flour resulted in whitish color in raw as well as fried snacks. However, the cooking time was more in the snacks fried directly from the frozen state (6.18 min) than the frozen-thawed fried snack (4.35 min). Quality of the snacks in terms of color values, appearance and texture was found to be superior to the thawed fried snack. During frozen storage of 16 months at -20 ± 1 °C, the overall acceptability (OAA) and lightness was found to be decreased from the original value. Rancidity parameters in terms of free fatty acids, peroxide value and thiobarbituric acid showed a restricted rise with the progression of storage period. The developed frozen snack was found to be microbiologically safe during the storage period.

Research progress of capsaicin responses to various pharmacological challenges.

Capsaicin, a well known vanilloid, has shown evidence of an ample variety of biological effects which make it the target of extensive research ever since its identification. In spite of the fact that capsaicin causes health hazards in quite a few ways, yet, the verity cannot be ignored that capsaicin has several therapeutic implications. In patients with hypersensitive bladders, vesical instillation of 1 mM capsaicin markedly improved urinary frequency and urge incontinence. Again, administration of capsaicin favors an augmentation in lipid mobilization and a decrease in adipose tissue mass. Topical capsaicin cream as well decreases postsurgical neuropathic pain and is preferred by patients over a placebo among other therapies. Several in vitro studies have revealed that capsaicin results in growth arrest in some transformed cell lines. Furthermore, capsaicin has been proven to be an undeniably exciting molecule and remains a valuable drug for alleviating pain and itch. It has been recognized that capsaicinoids are the most potential agonists of capsaicin receptor (TRPV1). However, vanilloids could exert the beneficial effects not only through the receptor-dependent pathway but also through the receptor-independent one. The involvement of serotonin, neuropeptide Substance P and somatostatin in the pharmacological actions of capsaicin has been expansively investigated. Better understanding of the established TRPV1 receptor mechanism as well as exploring other possible receptor mechanism may publicize other new clinical efficacies of capsaicin. Further, clinical studies are required in several of these conditions to establish the efficacy of capsaicin.

Impact of service attributes on customer satisfaction and loyalty in a healthcare context.

PURPOSE: The purpose of this paper is to examine the role of perceived service attributes in the development of overall customer satisfaction (OCS) and customer loyalty (CL) in a health-care setting. This paper also sheds light on the role of hospitalist physicians (HPs) and offers suggestions to improve patient satisfaction and loyalty. DESIGN/METHODOLOGY/APPROACH: A telephone survey was used to collect data from recently hospitalized patients with respect to their HP. Structural equations modeling (SEM) was used to confirm the overall relationships between perceived service quality (PSQ), OCS and CL. The sample was then divided into customer relationship groups (CRGs) based on satisfaction and loyalty measures. Discriminant analysis was used to determine which attributes differentiated most between high and low satisfaction and loyalty groups. FINDINGS: Overall relationships among PSQ, OCS and CL were in conformity with the conceptual model. Findings also revealed that service attributes played an important role in distinguishing between high and low satisfaction and loyalty groups, although some attributes were more important than others and different attributes emerged as being key influencers for satisfaction and loyalty. RESEARCH LIMITATIONS/IMPLICATIONS: The conceptual model used is a fairly straight forward model, and we have not considered the impact of individual factors such as expectations and value perceptions or involvement levels and demographic characteristics on service quality and overall satisfaction. The data for this study were provided by a major health maintenance organization (HMO), and there is room for improvement in the manner in which certain constructs were measured. For example, OCS, recommendation and retention all used single item measures, and it might have been preferable to use multiple item measures for these constructs. PRACTICAL IMPLICATIONS: The study shows that organizations can benefit by identifying and focusing on critical attributes as part of their customer relationship management program. SOCIAL IMPLICATIONS: The SEM results provide strong support for the overall model linking service quality, OCS and CL in a health-care setting. As one would expect, PSQ has a strong impact on OCS, which, in turn, has a fairly strong impact on CL. However, there is also a significant direct linkage between PSQ and CL. This linkage shows that at least a certain portion of CL could evolve independent of the satisfaction level with the HP. This shows that, in addition to trying to improve satisfaction, organizations should also explore influencing loyalty directly, perhaps by the strategic use of service attribute perceptions. ORIGINALITY/VALUE: The study shows that customer perceptions at the service attribute level can often be the key to the generation and management of customer satisfaction and loyalty. It also has significance for how satisfaction and loyalty with HPs can be improved in a hospital setting.

Comparison of effects of yoga & physical exercise in athletes.

The effect of pranayama a controlled breathing practice, on exercise tests was studied in athletes in two phases; sub-maximal and maximal exercise tests. At the end of phase I (one year) both the groups (control and experimental) achieved significantly higher work rate and reduction in oxygen consumption per unit work. There was a significant reduction in blood lactate and an increase in P/L ratio in the experimental group, at rest. At the end of phase II (two years), the oxygen consumption per unit work was found to be significantly reduced and the work rate significantly increased in the experimental group. Blood lactate decreased significantly at rest in the experimental group only. Pyruvate and pyruvate-lactate ratio increased significantly in both the groups after exercise and at rest in the experimental group. The results in both phases showed that the subjects who practised pranayama could achieve higher work rates with reduced oxygen consumption per unit work and without increase in blood lactate levels. The blood lactate levels were significantly low at rest.

Influence of intensive yoga training on physiological changes in 6 adult women: a case report.

The short-term effects of 4 weeks of intensive yoga practice on physiological responses in six healthy adult female volunteers were measured using the maximal exercise treadmill test. Yoga practice involved daily morning and evening sessions of 90 minutes each. Pre- and post-yoga exercise performance was compared. Maximal work output (Wmax) for the group increased by 21%, with a significantly reduced level of oxygen consumption per unit work but without a concomitant significant change in heart rate. After intensive yoga training, at 154 Wmin(-1) (corresponding to Wmax of the pre-yoga maximal exercise test) participants could exercise more comfortably, with a significantly lower heart rate (p < 0.05), reduced minute ventilation (p < 0.05), reduced oxygen consumption per unit work (p < 0.05), and a significantly lower respiratory quotient (p < 0.05). The implications for the effect of intensive yoga on cardiorespiratory efficiency are discussed, with the suggestion that yoga has some transparently different quantifiable physiological effects to other exercises.

Effect of yoga on exercise tolerance in normal healthy volunteers.

Twelve normal healthy volunteers (6 males and 6 females) undergoing yoga training for 90 days were studied for the effect of yoga on exercise tolerance. Their ages ranged from 18 to 28 years. The volunteers were taught only Pranayama for the first 20 days and later on yogic asanas were added. Sub-maximal exercise tolerance test was done on a motorized treadmill by using Balke's modified protocol, initially, after 20 days (Phase-I) and after 90 days of yoga training (Phase-II). Pyruvate and lactate in venous blood and blood gases in capillary blood were estimated immediately before and after the exercise. Minute ventilation and oxygen consumption were estimated before and during the test. Post exercise blood lactate was elevated significantly during initial and Phase-I, but not in Phase-II. There was significant reduction of minute ventilation and oxygen consumption only in males in Phase-I and II at the time when the volunteers reached their 80% of the predicted heart rate. Female volunteers were able to go to higher loads of exercise in Phase-I and II.