Loss Of Soluble Solids Research Articles

The influence of microwave-assisted drying techniques on the rehydration behavior of blueberries (Vaccinium corymbosum L.)

The aim of this study was to determine the effect of: (a) different drying methods, (b) hot air temperature in a convection oven, and (c) the moisture content of fruits dehydrated by multi-stage drying which involves a transition between different stages of drying, on the rehydration kinetics of dry blueberries. Models describing rehydration kinetics were also studied. Blueberries dehydrated by multi-stage microwave-assisted drying, which involved a hot air pre-drying step at 80°C until the achievement of a moisture content of 1.95kgH2Okg−1DM, were characterized by significantly higher rates of initial and successive rehydration as well as smaller initial loss of soluble solids in comparison with the samples dried by other methods. The highest initial rehydration rate and the smallest loss of soluble solids after 30min of soaking were determined at 0.46min−1 and 0.29kgDMkg−1DM, respectively. The Peleg model and the first-order-kinetic model fit the experimental data well.

절단배추의 포장재질에 따른 단기 저장 중 품질특성

Fresh cut vegetables provide convenience and rapidity to consumers. However, they have a weakness with respect to their short shelf-life due to browning and quality degradation via increased respiration. To overcome this problem, the effect of packaging film on the short-term storage of cut kimchi cabbages was investigated. Polypropylene (PP), oriented polypropylene (OPP), and low-density polyethylene (LDPE) films were used as packaging film, and cut kimchi cabbages were stored in the packaging films at 5°C for 4 weeks. PP film packaging showed the least weight loss and soluble solids loss after 4 weeks. Titratable acidity increased during storage for all samples, however, the increase rate of titratable acidity in PP and OPP film packaging decreased, which was lower than that of LDPE film packaging. Color values decreased over time during storage. In appearance, PP film packaging was better than other films due to their high transparency. In a sensory test, there was no statistical difference among samples. Taken together, the transparent PP film packaging was more effective for short-term storage of cut kimchi cabbages. Thus, this study provides useful information for the selection of packaging materials for cut kimchi cabbage marketing.

A mathematical model of the effect of pH and food matrix composition on fluid transport into foods: An application in gastric digestion and cheese brining

The question of bioaccessibility of nutrients within a food matrix has become of increasing interest in the fields of nutrition and food science as bioaccessibility is the precursor to bioavailability. By analyzing the propagation of the wetting front of acidic water in raw carrot core and Edam cheese as model systems, we show that the diffusion of the acidic water is dependent on the pH of the gastric fluid and the food matrix. In addition, we demonstrate that the diffusion of NaCl during cheese brining is also dependent upon the concentration of the NaCl. This demonstrates that Fickian diffusion, along with a concentration dependent diffusion coefficient, is a valid model for describing concentration profiles in multiple food systems.Utilizing the diffusion rates found at various pH levels (1.50, 2.00, 3.50, 4.30, 5.25 and 7.00), we developed a model to describe the measured non-linear rate of soluble solid loss during digestion at various constant pH levels. Additionally, we have developed a model to predict the likely rate of soluble solid loss during digestion in the stomach where pH decreases with time. This model can be used to help understand and optimize the relationship between food structure/composition and food degradation in the human stomach, which may help in the development of novel foods with desired functionality.

Qualidade tecnológica do arroz branco polido submetido à irradiação gama (Co60)

A aplicação da radiação ionizante, com o propósito de garantir a segurança dos grãos, tem sido apresentada como alternativa eficaz e segura ao uso de defensivos agrícolas e prática promissora, a ser utilizada para estender a vida útil e reduzir as perdas das safras de grãos. Contudo, assim como outros tratamentos de conservação de alimentos, a irradiação pode alterar sua qualidade. Este trabalho foi realizado com o objetivo de avaliar a qualidade de cocção do arroz submetido a diferentes doses de irradiação gama Co60 (0,0 kGy, 6,5 kGy e 7,5 kGy). Observou-se que o arroz irradiado com 7,5 kGy apresentou um tempo de cozimento significativamente maior (18,21 min.) que o do arroz irradiado na dose 6,5 kGy (17,11 min) e 0,0 kGy (16,83 min.). Os valores médios de expansão do volume do arroz não irradiado foi de 365,65%; já, para o arroz irradiado, os valores foram menores, apresentando-se com 322,19%. Quanto à perda de sólidos solúveis, essa foi significativamente maior no arroz branco polido irradiado (17,0%), do que no arroz não irradiado (10,35%). Embora a irradiação gama tenha influenciado em alguns parâmetros de cocção do arroz, refletindo-se em maior tempo de cozimento, para a irradiação na dose 7,5 kGy, no menor coeficiente de expansão do volume e na maior perda de sólidos solúveis, os valores encontrados assemelham-se aos valores referenciados, na literatura, como desejáveis para a qualidade deste cereal.

Nutraceutical Properties of Flour and Tortillas Made with an Ecological Nixtamalization Process

The traditional nixtamalization (TN) process, used for obtaining maize-based products, negatively affects bioactive compounds because of its highly alkaline pH. Recently, an ecological nixtamalization (EN) process has been developed that retains the pericarp and maintains the nejayote (wastewater) within the acidic-neutral range. This study examines the effect of pH on the nutraceutical compounds (NC) of maize, such as polyphenolics and anthocyanins (ANT), as well as the effect on the antioxidant capacity (AC). The highest concentration of total phenolics (TP) in the maize kernel was found in the black and yellow genotypes, the highest concentration of ANT in the black genotypes, and the highest concentration of AC in the red and white genotypes. In the flour, TP levels were between 206 to 400 mg GA/100 g, ANT levels were 141 to 4107 mg cyanidin-3 glucoside/kg, and AC levels were 2544 to 3001 mg AA/kg. In tortillas, TP levels were 255 to 319 mg GA/100 g, ANT levels were 32 to 3420 mg cyanidin-3 glucoside/kg, and AC levels were from 1513 to 2695 mg AA/kg. The reduced loss of soluble solids, the pH, and the formation of compounds with proteins and carbohydrates from the EN process positively affected NC retention.

Quality of 'Delta Valencia' orange grown in semiarid climate and stored under refrigeration after coating with wax

The effects of carnauba-based wax on the quality of ‘Delta Valencia’ orange produced in Ceara state, Brazil, were studied. The fruits were coated with carnauba-based wax and refrigerated (7 ± 2 °C and 85 ± 2% R.H.) for 28 days. The quality attribute parameters assessed were weight loss, peel color (brightness, hue angle, and chromaticity), peel moisture, pH, soluble solids (SS), titratable acidity (TA), SS/TA ratio, ascorbic acid, total soluble sugars, reducing sugars, yellow flavonoids, and polyphenols. The results showed that ‘Delta Valencia’ oranges grown in the dry climate of Ceara state has excellent quality. The coated fruits lost mass at a lower rate than the the control fruits. No significant loss of soluble solids, titratable acidity, pH, and SS/TA ratio was observed, while ascorbic acid, soluble sugars, reducing sugars, yellow flavonoids, and polyphenols increased during storage in both the coated and control fruits. Carnauba-based wax coated fruits showed no signal of dehydration keeping their shiny green peel up to the end of the storage. The use of coating was crucial for the maintenance of visual quality by reducing mass loss, as well as keeping peel moisture.

THE EFFECTS OF ADDING SOY FIBER TO WHEAT SPAGHETTI

This study has evaluated the effects of adding 4%, 6% and 8% soy fiber to wheat pasta for the production of dry wheat spaghetti. The properties of the mixture were evaluated for humidity, falling number, ashes, color, retained gluten, and subjected to farinograph (water absorption, development, stability) and extensograph analyses (resistance and extensibility). The spaghetti was evaluated with cooking tests (performance, increased volume, loss of soluble solids to cooking water) and sensory analysis. The addition of soy fiber to wheat flour resulted in mixtures with rheological and physicochemical characteristics suitable for the production of wheat spaghetti, enhancing performance and reducing the loss of soluble solids to the cooking water. The sensory analysis showed that, for all parameters tested, panelists favored mixtures with up to 6% soy fiber addition.

Comparison of Solid-Liquid Separation (SLS) and Vacuum Concentration of Tomato Juice

Hot break, cold break and commercially canned tomato juice was concentrated by vacuum concentration and solid-liquid separation (SLS). Tomato products from vacuum concentration had higher soluble solids than those from SLS because of loss of soluble solids into the filtrate. Most volatile levels in vacuum concentration greatly decreased initially then remained constant during further concentration. In SLS, volatile levels linearly decreased with increasing concentration so SLS had greater retention of volatile compounds than vacuum concentration. Viscosity of the rediluted samples decreased with concentration, except in the hot break and commercial samples from SLS, which maintained the same viscosity. Samples from SLS were close to the original color while vacuum concentration was redder due to heat-induced Maillard browning. Vitamin C decreased during concentration with greater loss during SLS than vacuum concentration. SLS consumed 45 times less electric power energy than vacuum concentration, which also needed water for creating vacuum conditions. Practical Applications Solid-liquid separation (SLS) is a new technology for dewatering products, such as concentration of tomato juice. SLS does not need heat to concentrate the product; therefore, the processor may be able to reduce energy consumption while better preserving flavor and viscosity of the product.

Moisture sorption isotherms of fresh and blanched pumpkin (Cucurbita moschata)

Moisture desorption isotherms of fresh and heat blanched pumpkins (Cucurbita moschata) were determined at three temperatures (30, 50 and 70 °C), using the standard, static-gravimetric method. The GAB, Oswin, BET, Halsey, and Henderson models were tested and, with the exception of the Henderson model, showed satisfactory fits to the experimental data. The GAB model was used to analyze the fitting ability to describe the isotherm type. The shape of the desorption isotherms of fresh and blanched pumpkin at 30 and 50 °C was intermediate to types II and III, and at 70 °C it was of type II for the blanched pumpkin and close to type II for the fresh sample. The influence of blanching on the decrease in equilibrium moisture was very small compared to the fresh samples and it was related to the loss of soluble solids during the pre-treatment. The isosteric heat of sorption measures indicated that a larger amount of heat was required to remove the water from the fresh samples than from the blanched ones.

Physiological, Volatile, and SEM Surface Effects Resulting from Cutting and Dipping Treatments in Cantaloupe

Previous research examined sanitation treatments on cut cantaloupe tissue to deliver germicidal and food safety effects. However, an apparent compromise between volatile loss and treatment/sampling efficacy appeared. Subsequently, a physiological and volatile reassessment of thinly sliced tissue against cubes was performed in cantaloupe tissue. Thin sliced cantaloupe L* decreased 27.5%, 40.5%, and 52.9% in 3, 2, and 1 mm thickness, respectively, compared with cut cubes after 3 d. Overall color (C) decreased in freshly prepared cubes (2.4%) and slices (14.4%) that were washed in cold water. Surface area per unit volume (SA: vol) in slices was 4.1 times greater than typical cubes, as reflected by substantial water loss (20.4%, 9.5%, and 6.7% in 1, 2 and 3-mm slices, respectively) after 1 d at 5 °C. Rinsing cubes and thin-slices with 5 °C deionized water resulted in roughly 15% soluble solids loss. SEM indicated 65.4% reduced cell size in 1-d old thin slices, evidenced by excessive cell damage and desiccation compared with stored fresh-cut cubes. In thin-sliced tissue exposed 15 min to an open atmosphere (mimic sanitation treatments), total esters decreased 92.8% and 95.8%, respectively, after 1 and 3 d storage at 5 °C. Washing tissue provided a boundary layer that reduced short-term ester losses in slices and cubes. Excessive cutting, sanitation treatment regimes, and storage can radically alter the desirable volatile profile of cut cantaloupe. Reduction of tissue size to maximize food-safety sanitation efficacy or delivering items to a niche market will need substantial work to engineer equipment and develop protocols to insure that product quality and volatiles are not compromised. We have demonstrated that cutting method and sampling protocol are critically important when using volatiles as a means by which to assess or interpret stress response and ascribe fresh-cut quality. Reduction of tissue size to maximize food-safety sanitation efficacy (for example, thin slices) will need substantial work to engineer equipment and design protocols to insure product quality and volatile profiles are not compromised.

SOLID LOSS DURING WATER ABSORPTION OF CHICKPEA (CICER ARIETINUM L.)

ABSTRACT Soluble solid leached out during soaking and cooking of food legumes generally decreases the overall quality of the final products. Solid loss behavior of whole chickpea during soaking and cooking in water was investigated at 20, 30, 50, 70, 85 and 100C. The amount of solid loss and its rate increased with increasing temperature, and the former was 2.3% at 20C and 10.2% at 100C at the end of the process. Carbohydrates and proteins composed of 80–91% of the solid lost. A zeroth‐order kinetic model fit the solid loss data. The solid loss rate constant (kds) increased with temperature, and it was 4.7 × 10−5/s at 20C and 240.3 × 10−5/s at 100C. Effect of temperature on kds was determined using an Arrhenius‐type equation. The Arrhenius plot exhibited two linear lines crossing at the gelatinization temperature (61C) of the whole chickpea. The activation energy was determined to be 59.5 and 22.6 kJ/g/mol above and below the gelatinization temperature, respectively.PRACTICAL APPLICATIONSSoaking and cooking are the two main steps during processing of chickpea. Soluble solid loss into the soaking or cooking water generally decreases the nutritional and economic value of the final product and it is one of the quality indicators of the dry, soaked and soaked/cooked legumes. In the current study, soluble solid loss from whole chickpea seeds during soaking and cooking in water were studied as a function of time and temperature. Results from the current study can be useful in designing the process parameters of soaking and cooking and for the evaluation of the quality of dry or processed whole chickpea.

INFLUENCE OF DRYING METHOD ON THE REHYDRATION PROPERTIES OF APRICOT AND APPLE

ABSTRACTThis study aims to determine the influence of microwave drying coupled with air drying of apricot and apple in terms of the rehydration rate and capacity of dried samples. The microwave power level was 0.4 W/g for apricot and 0.5 W/g for apple samples. The effect of air temperature (50 and 30C) and vacuum impregnation pretreatment (with a commercial isotonic juice) was examined. The sample mass change, water gain and soluble solids loss, were obtained before sample rehydration (in distilled water at 20C for 8 h). Peleg's model was used to assess the effect of process conditions on rehydration kinetics, with a good fit of the experimental data. Taking into account the lower values for Peleg's constants of k1(i) and k2(i), the vacuum impregnation pretreatment and microwave application to air drying allow us to obtain a dried product with a better rehydration capacity, promoting the rate and capacity of water gain and solute loss, although the structure of product remains with a lower liquid phase retention capacity. A less relevant influence of air temperature on water gain kinetics was observed, improving the rehydration ratio only for nonvacuum‐impregnated samples.PRACTICAL APPLICATIONSDehydration is widely applied to food preservation in stable and safe conditions. Dried and rehydrated fruits are key ingredients in dairy products, breakfast cereals, dietetic foods formulated for people suffering from physiological disorders or for healthy people with additional needs and traditional foods such as puddings, desserts, cakes, biscuits. Rehydration product behavior must be known when a total or partial reconstitution is required. This work provides information on the influence of microwave‐assisted air drying method and vacuum impregnation pretreatment on the rehydration capacity and kinetic analysis of dried apricot and apple, in order to obtain rehydrated foods in accordance with the requirements in further processing and consumer expectations.

Effluent content from albedo degradation and kinetics at different temperatures in the enzymatic peeling of grapefruits

This work studies the variation in the effluent content from the reactor in enzymatic peeling of grapefruits, to determine the loss of soluble solids, reducing sugars and galacturonic acid, the main component from the albedo of the skin to model the solid–liquid transfer in this process. Experiments to study the efficiency of the enzymatic reaction include the effect of the temperature on the kinetics of albedo degradation to find an equation relating both variables and also the activation energy of this process, its value being 36.9 kJ/mol.

Rapid screening methods to evaluate cowpea cooking characteristics

Current methods of evaluating cooking quality of grain legumes are inefficient and costly. As a result, breeders tend to delay cooking quality evaluations until late in the breeding process after the number of breeding lines has been markedly reduced. Cooking quality evaluations conducted earlier in the process, when genetic variation for these traits is high and can be exploited by selection, would maximize the probability of developing cultivars with greater functionality and consumer acceptability. This study aimed to develop a rapid, low-cost screening method to evaluate the cooking quality attributes of cowpea ( Vigna unguiculata L. Walp.) dry grain. Replicate samples (5 g) of 56 genetically diverse cowpea cultivars grown in either one or two environments, were soaked for 16 h, boiled for 27 min, and grain and their broth separated for evaluation. The samples were evaluated in batches of 25 and were subjectively rated on a 1–5 scale for cooked doneness, tactile texture, aroma intensity and opacity of the broth. Water absorption, seed splitting, and soluble solid loss were also determined. The method differentiated the cowpea samples in terms of cook doneness, tactile texture, bean and broth aroma and broth opacity. Cooked properties showed significant correlations with each other, but did not correlate with either uncooked grain size or seed coat color. Compression force determined with a texture analyzer (TA) and cooking times from the Mattson Bean Cooker (MBC) significantly correlated with doneness and tactile texture ratings done with the rapid technique, confirming the applicability of the subjective ratings. A procedure to determine solid losses during cooking using a refractometer, instead of the time-consuming oven-drying method, saved time and showed significant promise. The rapid cooking method requires 2 h on the first day (sample preparation and soaking) and 5 h on the second day (cooking and evaluation) to evaluate 25 samples (1 rep). The method is efficient, repeatable and uses inexpensive equipment and materials. It provides descriptive information on aroma and organoleptic properties and differentiates cowpea cultivars based on several important cooking properties. This method should be a useful tool for selecting cowpea breeding lines with desirable cooking characteristics and it should be possible to extend the method to other grain legumes with only slight modification. This method may also be useful in preliminary determinations of whether specific lots of grain meet specifications for purchase and processing.

Quality of Jerusalem artichoke (Helianthus tuberosus L.) tubers in relation to storage conditions.

The influence of storage conditions on quality parameters of Jerusalem artichoke cv. 'Swojecki' was investigated. Tubers were kept in a cold chamber at the temperature of 20C and RH 90-95% for a period of four months. Three methods of storage were applied: in polypropylene (PP) net bags, in the sand or the peat. During storage period there were systematically determined, using standard methods: weight loss, dry matter, soluble solids, total and reducing sugars content and sucrose content. Results showed that the method of storage strongly affected quality degradation of the tubers. The biggest weight loss after two months of storage were noticed for tubers kept in PP net bags. Storage in the sand or the peat significantly reduced weight loss. When tubers were kept in PP net bags, dry matter after four months of storage was 2.2 times bigger, compared with tubers kept in the sand or the peat. The highest loss of soluble solids (4%) was found after four months of storage in the case of storage tubers in PP net bags. Irrespective of storage conditions, the lowest content of total sugars and sucrose in tubers were found after two months of storage. The biggest concentration of reducing sugars in tissue was found in tubers kept in PP net bags.

Abrupt changes in the rates of processes occurring during hydrothermal treatment of whole starchy foods around the gelatinization temperature––a review of the literature

The rate of processes such as water transfer, gelatinization, loss of soluble solids, volumetric expansion etc. occurring during hydrothermal treatment of whole starchy foods exhibits one common behavior: The plots of the rate constant specific to the given process versus temperature give a break-point temperature ( T bre) around the gelatinization temperature ( T gel). Some workers connected this phenomenon to starch gelatinization. The review of the pertinent works exhibited that the T bre values are in the ranges of the gelatinization temperatures given in the literature. These ranges are large enough that the observed T bre values could readily be within or close to them. The break-point phenomenon may potentially be a non-invasive simple method for determining the T gel in whole starchy foods, e.g. in situ T gel. This potential must be tested on different types of starchy foods by comparing the T bre with measured T gel of the same sample.

Kinetics of osmotic dehydration of a highly shrinking vegetable tissue in a salt-free medium

The kinetics of water removal and solute uptake during osmotic dehydration of a highly shrinking vegetable tissue (potato) in a salt-free osmotic medium (corn syrup solids) were studied. Increased temperatures (up to 45 °C) gave highly increased rates of dehydration and net loss of soluble solids ranging between 4.4 and 13.4% of total initial solids. Half dehydration time at 50 °C, was half of that measured at room temperature. Processing at 50 °C, however, was followed by extensive, nearly linear (with time) sugar uptake, reaching 50% of initial solids within 5 h. Half dehydration time and mass (water) diffusivity followed Arrhenius type kinetics with activation energies of 21.2 and 28.7 kJ mole −1, respectively. Shrinkage experiments revealed a very strong correlation between the rate of volume decrease and the rate of moisture removal. Within the industrially applicable processing time, volume of removed water was identical to shrinkage induced loss of product volume. Concentrated solutions of corn syrup solids seem to be suitable for efficient osmotic dehydration of potato-like vegetable tissues, without suffering the negative impact of extensive solute uptake.

Measurement of Provitamin A Carotenoids in Fresh and Canned Carrots and Green Peas

ABSTRACTThe influence of thermal processing (canning) on the carotenoid content of carrots (Daucus carota) and green peas (Pisum sativum) was investigated. Carotenoids extracted from fresh and canned vegetables were separated by column chromatography and quantified using spectrophotometric analysis. Canned canots and green peas had a higher carotenoid content than fresh samples. The apparent increase in canned carrots was mainly due to the loss of soluble solids into the brine during processing. However, the increase of carotenoids in canned green peas was due to the loss of carotenoids by enzymatic activity in fresh green peas during extraction procedures.

Nutrient Losses in Runoff from Conventional and No‐Till Corn Watersheds

AbstractA study was initiated to determine the quantity of nutrients and sediment in runoff from conventional and no‐till corn (Zea mays L.) watersheds. Runoff was collected with H‐type flumes and Coshocton wheels. Parameters measured in runoff included NH4+‐N, NO3−‐N, total N, ortho‐PO4, total soluble P, total P, suspended sediment, and soluble solids.There was a significant difference in total runoff between the conventional and no‐till watersheds. Over nine times more runoff originated from the conventional‐till watershed when compared with the no‐till watershed in 1982. A large difference between the two watersheds in suspended sediment content was also observed. Yearly sediment losses of 370 and 9 kg ha−1 from the conventional and no‐till watersheds, respectively, were found for 1982. There was also a significant difference in the loss of soluble solids between the two watersheds. For 1982, there was over a 29‐fold greater loss of soluble solids from the conventional‐till watershed than from the no‐till watershed.Losses of NH4+‐N, NO3−‐N, and total N from each watershed were very low, although large differences were observed between the two watersheds. In 1980, 271, 638, and 1199 g ha−1 of NH4+‐N, NO3−‐N, and total N, respectively, were lost from the conventional‐till watershed, while 2, 47, and 87 g ha−1, respectively, of the above parameters were lost from the no‐till watershed.The loss of all forms of P from each watershed was also very small. During 1982, 161 g ha−1 of total P were lost from the conventional‐till watershed while only 8 g ha−1 were lost from the no‐till watershed. The loss of ortho‐PO4 and total soluble P was not significantly different between the two tillage treatments.

Apple Juice Quality and Recovery from McIntosh Apples Stored in Controlled Atmospheres and Air

Storage of whole McIntosh apples (Malus domestica Borkh.) in 0°C air resulted in a rapid decline in soluble solids, titratable acids, and tannin content and increased haze in the extracted juice. The use of conventional controlled atmospheres (5.0% CO2 + 3.0% O2, 2.8°C) retarded the loss of soluble solids and titratable acids in the juice and partially suppressed volatile development and haze formation during the initial storage period. Low oxygen storage (1.5% CO2 + 1.0% O2, 2.8°C) further suppressed titrable acids loss, volatile development and haze formation after subsequent air storage, indicating potential for the production of high quality apple juice over an extended processing period. Storage treatments had no significant effect on juice yields which ranged from 76.9 to 79.7%.