Moisture Foods Research Articles

Measurement of the Water-Diffusion Coefficient, Apparent Density Changes and Shrinkage During the Drying of Eggplant (Solanum Melongena)

The aim of this work was to estimate shrinkage, apparent density changes, and the effective diffusion coefficient of water, Deff , during eggplant drying. Drying experiments were performed using a halogen moisture analyzer. This technology has several advantages over the traditional methods reported in the literature, as it is quite inexpensive, requires less energy, and, in principle, can be used for many different types of foods. The experimental data were interpreted using a classical mathematical model that describes the transient mono-dimensional transport of water in food to estimate Deff . Under the experimental conditions examined, the Deff, was found to range from 1.13.10−10 to 5.65.10−10 m2/s. Shrinkage modelling revealed a non-linear dependence of food sample volume on the food's moisture content. In addition, while the apparent density of the food did not change appreciably during the first period of drying, a marked decrease was observed during the final drying period.

Pressure Effect on Deep Fat Frying of Apple Chips

Predicting moisture loss is important when developing a model for vacuum frying, because one of its objectives is to remove food moisture. A diffusion model was considered to describe moisture transfer during vacuum frying. Granny Smith apple slabs were processed at 16.6, 13.3, and 8 kPa and between 80 and 120°C. Moisture diffusivity was determined, obtaining a close fit between the model and the experimental data. Diffusivity increased with temperature and decreased when pressure increased. A direct proportionality between heat and mass transfer was observed. Temperature influence was interpreted by the Arrhenius relationship and there was no observed effect of pressure on the activation energy.

Molecular thermodynamics modeling of equilibrium moisture in foods

Moisture content in foods affects many aspects of processing and storage, as well as quality and pathological activity. Understanding its behavior is very important in the food industry for designing effective long-term food management strategies, in particular transportation and storage. Most approaches found in the literature dealing with moisture in foods consist of measuring it as a function of relative humidity and temperature and then fitting the data to empirical or semi-empirical models for interpolation or correlation purposes. Most semi-empirical models are modifications of early gas adsorption models on hard surfaces, which fundamentally are not well suited to describe water in softer materials such as foods. In this work, we propose and use a more general framework based on equilibrium molecular thermodynamics to model and correlate equilibrium moisture content (EMC) in foods that takes into account other non-adsorption phenomena such as mixing and swelling of the biopolymers in foods. The framework is general, and the current model shows very good results correlating and modeling EMC. The model parameters provide insight into the nature of the water activity in food products, providing potentially useful information for food processing and modeling.

Contributors of water intake in US children and adolescents: associations with dietary and meal characteristics—National Health and Nutrition Examination Survey 2005–2006

Little is known about the association of contributors of total water intake with dietary characteristics in US children. We examined intakes of total water and its contributors and their associations with diet and meal reporting in children and adolescents. Dietary data for children 2-19 y of age (n = 3978) from the National Health and Nutrition Examination Survey 2005-2006 were used to compute usual intake of total water. The association of total water and its contributors with sociodemographic characteristics and dietary and meal attributes was examined by using multiple regression analysis. The adjusted mean intakes of total water in Americans aged 2-5, 6-11, and 12-19 y were 1.4, 1.6, and 2.4 L, respectively. The mean usual intake of total water was generally less than the Adequate Intake; overall, more boys reported intakes of at least the Adequate Intake. The percentage of total water intake from plain water increased with age. Plain water intake was inversely associated with the intake of beverage moisture and the energy density of foods; conversely, beverage moisture was positively associated with dietary energy, fat, and the energy density of foods. Associations of water contributors with meal patterns (number of eating occasions, reporting of breakfast or snack) were inconsistent across age groups. Nearly 80% of food moisture, >66% of beverage moisture, and ≈30% of plain water were reported with main meals. Intake of total water over 24 h from different contributors varied by age. Qualitative differences in dietary intake in association with the amount of plain water and beverage moisture in the recalls were observed. American children and adolescents consumed more than two-thirds of their daily beverages with main meals.

Scientific Opinion on Dietary Reference Values for water

This Opinion of the EFSA Panel on Dietetic Products, Nutrition, and Allergies (NDA) deals with the setting of dietary reference values for water for specific age groups. Adequate Intakes (AI) have been defined derived from a combination of observed intakes in population groups with desirable osmolarity values of urine and desirable water volumes per energy unit consumed. The reference values for total water intake include water from drinking water, beverages of all kind, and from food moisture and only apply to conditions of moderate environmental temperature and moderate physical activity levels (PAL 1.6). AIs for infants in the first half of the first year of life are estimated to be 100–190 mL/kg per day. For infants 6–12 months of age a total water intake of 800 1000 mL/day is considered adequate. For the second year of life an adequate total water intake of 1100 1200 mL/day is defined by interpolation, as intake data are not available. AIs of water for children are estimated to be 1300 mL/day for boys and girls 2–3 years of age; 1600 mL/day for boys and girls 4–8 years of age; 2100 mL/day for boys 9–13 years of age; 1900 mL/day for girls 9–13 years of age. Adolescents of 14 years and older are considered as adults with respect to adequate water intake. Available data for adults permit the definition of AIs as 2.0 L/day (P 95 3.1 L) for females and 2.5 L/day (P95 4.0 L) for males. The same AIs as for adults are defined for the elderly. For pregnant women the same water intake as in non-pregnant women plus an increase in proportion to the increase in energy intake (300 mL/day) is proposed. For lactating women adequate water intakes of about 700 mL/day above the AIs of non-lactating women of the same age are derived.

Intakes of plain water, moisture in foods and beverages, and total water in the adult US population—nutritional, meal pattern, and body weight correlates: National Health and Nutrition Examination Surveys 1999–2006

BackgroundThere is a surprising paucity of studies that have systematically examined the correlates of water intake in the US population. ObjectiveThe objective was to examine the association of contributors of water intake with dietary characteristics, meal consumption, and body weight in the US population. DesignWe used 24-h dietary recall data from the National Health and Nutrition Examination Survey (NHANES) 1999–2004 (n = 12,283) and the NHANES 2005–2006 (n = 4112) to examine the independent association of intakes of plain water, beverage moisture, food moisture, and total water with sociodemographic factors, dietary characteristics (energy, nutrients, diet quality, and energy density), and meal patterns (number of eating episodes, mention of breakfast or snack) by using multiple regression methods. ResultsIn 2005–2006, American adults reported consuming 3.18 L of total water within the previous 24 h (in 1999–2004, estimated total water intake was 3.35 L), with plain water and beverages contributing 33% and 48% of the total, respectively. Plain water intake was unrelated to the intake of energy and body mass index but was positively related to dietary fiber and inversely related to beverages, sugars, and the energy density of foods; these associations were in the opposite direction for beverage moisture intake. Total water intake was inversely related to energy from fat and energy density but positively related to dietary fiber, caffeine, alcohol, and diet quality. The number of eating episodes predicted higher beverage and food moisture and total water intakes. A higher body mass index predicted higher intakes of beverage moisture and total water. ConclusionVarious contributors of total water intake differed in their association with dietary characteristics and body weight in the adult US population.

Bioenergetic strategy of a xylem-feeder

To understand the efficiency of energy flow through an organism living in a nutrient poor environment, the bioenergetics of a xylem-feeding beetle Aredolpona rubra was investigated. The larvae of different ages were kept at a constant high, constant low and seasonally variable temperature or in agar plates and agar + nitrogen plates. Bioenergetic parameters were measured during the course of 1 year. The results showed (i) a very strong influence of food moisture on the bioenergetic parameters of A. rubra, (ii) the influence of temperature depends on whether it is fluctuating or constant, (iii) opposite mechanisms regulate growth in a shortage of water and at a suboptimal temperature: in the former case, consumption does not change while the metabolic rate decreases, and at a suboptimal temperature the metabolic rate is dictated by temperature and the consumption rate is altered and (iv) a nitrogen-rich diet results in a decreased metabolic rate, suggesting the existence of energetically costly adaptations to low quality wood as a food source. The study results have broad implications for environmental influences on insect life histories.

바이오에너지로의 전환을 위한 캘리포니아 식품가공공장 오.폐수 특성 조사 및 경제성 분석

This research expands investigations into the biomass resource potential associated with California`s food processing industry by surveying industries within a two county region in the San Joaquin Valley, California, USA. A previous survey conducted in 2005 for the Sacramento Municipal Utility District (SMUD) quantified residue and waste generation from food processors and food preparation businesses in the Sacramento region. The present survey investigates residue and waste streams from food processors located in Merced and Stanislaus Counties. Sixty food processors were identified to participate in the survey, of which 49 responded (82%) and data were acquired for 38 (63%) (6 facilities closed or moved, 8 decided not to participate). Within the two counties, total annual waste among survey respondents amounted to 24,044 dry tons of high moisture (60%) food residuals, 5,358 dry tons of low moisture ( of wastewater containing 38,814 tons of biochemical oxygen demand (). The total potential electric power generation from these food residues was estimated at approximately . Total solid waste resource included in the survey response was estimated at about 10% of statewide residue generation for processors falling within the Standard Industrial Classification (SIC) System Major Group 20 (Food and Kindred Products) categories.

Water intake, nutrient intake, and body mass index among U.S. adults: Results from What We Eat in America/ NHANES 2005‐2006

This study sought to determine if intakes of water (moisture) from food and from beverages are associated with nutrient intakes and body mass index (BMI) among U.S. adults. Inverse associations between moisture from foods (but not beverages) and BMI have been detected by others, but those findings were not nationally representative for the U.S. Men and women age 19 years and older (n = 4,405) with one complete 24‐hour dietary recall in What We Eat in America (WWEIA)/NHANES 2005‐2006 were divided into quartiles based on their moisture intake from food and from beverages. Regression procedures adjusting for confounding factors were used to detect associations between moisture from each source and nutrient intakes and BMI. Nutrients studied were those for which >10% of Americans obtained less than the Estimated Average Requirement or Adequate Intake. Food moisture was positively associated with all nutrients analyzed (p < .01). Associations with beverage moisture were fewer and some were negative; e.g., higher beverage moisture was related to lower fiber intake in men. Beverage moisture was positively associated with BMI in men. No other associations between source of moisture and BMI were found. Overall, although higher one‐day food moisture intake is associated with higher intakes of selected nutrients, it is not associated with lower BMI in the U.S. adult population. Funding source for this study is USDA.

Comparison of the guaranteed analysis with the measured nutrient composition of commercial pet foods

To compare guaranteed and measured concentrations of nutrients in commercial pet foods. Cross-sectional study. Annual inspection reports of pet food analyses from 5 states. Guaranteed and measured concentrations of crude protein (CP), crude fat (CF), crude fiber (CFb), moisture, and ash in pet foods were compared. The concentration difference for each nutrient was compared among types of food, target species, target life stages, manufacturers, and laboratories. The guaranteed and measured concentrations of nutrients were significantly different. For all foods, mean concentration differences were as follows: CP, 1.5%; CF, 1.0%; CFb, -0.7%; moisture, -4.0%; and ash, -0.5%. Crude protein difference for treats was significantly larger than differences for dry and canned foods. Crude fat difference for dry foods was significantly less than differences for canned foods and treats. Crude fiber and moisture differences for canned foods were significantly less than the corresponding differences for dry foods and treats. Only CFb differences differed among target species, life stages, manufacturers, or laboratories. Addition of 1.5% and 1% to the guaranteed minimums for CP and CF, respectively; subtraction of 0.7%, 4%, and 0.5% from the guaranteed maximums for CFb, moisture, and ash, respectively; and addition of 0.23 kcal/g to the as-fed metabolizable energy value calculated by use of modified Atwater factors from guaranteed analyses provides a more accurate estimate of the nutrient and metabolizable energy content of commercial pet foods. Nevertheless, the actual composition of a food should be determined whenever possible.

Metabolizable energy intake during long-term calorie restriction in rhesus monkeys

Calorie restriction (CR) is a dietary intervention shown to increase maximum life-span. The aim of this study was to compare the metabolizable energy of the pelleted semi-purified diet with estimated energy intake from food weight. Energy density of diet, urine and feces were measured by bomb calorimetry in rhesus monkeys (23–29 years old) on CR (CR, n = 11) and control (C, n = 9). Food moisture was measured to be 2-fold higher (9 ± 1%) than indicated on the label (∼5%). The measured gross energy of diet was 4.4 kcal/g dry weight of CR and 4.5 kcal/g dry weight of C diets. In a two-day trial, food intake (mean ± SD) was 112 ± 20 g and 136 ± 26 g of dry mass/d in the CR and C monkeys, respectively ( p = 0.003). The fraction of the diet absorbed (CR = 0.91; C = 0.95) was different ( p < 0.001) between CR and C monkeys. Using these coefficients, the metabolizable energy intake averaged over 6 months was 450 ± 53 and 534 ± 97 kcal/d in CR and C monkeys, respectively (Diff = 16%; p = 0.03). These values were compared with energy expenditure (EE), as measured annually by indirect calorimetry (490 ± 61 kcal/d in CR and 532 ± 62 kcal/d in C monkeys). Adjusted for changes in body composition (2 ± 10 kcal/d in CR and −7 ± 12 kcal/d in C), energy balance was not different from zero in CR (−42 ± 42 kcal/d) and C (9 ± 61 kcal/d) monkeys. Use of diet weight is a reasonable estimate of the level of CR when food waste is assessed.

Landscape Mulches and Termite Nutritional Ecology: Growth and Survival of Incipient Colonies of &lt;I&gt;Coptotermes formosanus&lt;/I&gt; (Isoptera: Rhinotermitidae)

Alate swarms are one of the major visible signs of the expansion of the Formosan subterranean termite, Coptotermes formosanus Shiraki (Isoptera: Rhinotermitidae), in an area. Successful establishment of an incipient colony is thought to mainly rely on available food resources and moisture. The large-scale use of tree-based mulches in landscapes may inadvertently contribute to local establishment and growth of C. formosanus colonies. This research investigated the nutritional ecology of incipient colonies of C. formosanus feeding on seven tree-based, weathered, and nonweathered landscape mulches: pine straw, pine bark, cedar wood, water oak, eucalyptus, cypress, and melaleuca. Incipient colonies of C. formosanus feeding on pine straw, either weathered or nonweathered, produced significantly more progeny over the course of 1-yr feeding than colonies feeding on the other mulches tested. Regardless of weathered or not, the incipient colonies feeding on pine straw, eucalyptus, bald cypress, and water oak mulches had significantly greater survival rates after 360 d (53-77%) than colonies feeding on the other mulches tested (0-13%), but colonies feeding on nonweathered water oak had significantly lower survival (8%) than those kept on weathered water oak (58%). Colony fitness values were significantly different between the weathering treatment groups and among the different types of mulches. With regard to colony growth characteristics, three distinct growth patterns were identified: a high number of progeny (>100) with high colony survival rate (>50%), a medium number of progeny (12-50) with high colony survival rate (>50%), and a small number of progeny (0-10) with low colony survival rate (<5%). These findings suggest that different types of mulch substrates could significantly impact the nutritional ecology of the founding pairs and the successful establishment of incipient colonies during the swarming season.

Determination of Moisture Sorption Isotherms of Jasmine Rice Crackers Using BET and GAB Models

Moisture sorption isotherms of Thai Jasmine rice crackers were determined at 30, 45 and 60°C over a water activity range of 0.10 to 0.95 using a static gravimetric technique. Moisture sorption isotherms of rice crackers exhibited the sigmoid (Type II) shape. The moisture content of rice crackers decreased as temperature increased at a given water activity of the storage environment. The Brunauer, Emmett and Teller (BET) and Guggenheim-Anderson-de Boer (GAB) models were applied to fit the experimental data. The isosteric heat of sorption at different moisture levels was also determined using the Clausius–Clapeyron thermodynamic equation. A nonlinear regression analysis method was determined to evaluate the parameters of sorption equations. The criteria used to evaluate the goodness of fit of each model were the mean relative percentage deviation modulus (E) and the percentage root mean square error (RMSE). The more extended range of application of the GAB equation over the BET equation was evident. The GAB model gave the best fit to the experimental sorption data for a wide range of water activity (0.10–0.95) while the BET model gave the best fit for a water activity range of less than 0.60. The GAB model is considered suitable to predict the moisture sorption isotherm of rice crackers since it gave low E and RMSE values. The heat of sorption values of rice crackers were found to be large at low moisture content and decreased with an increase in food moisture content.

Genetic diversity and differentiation of cultivated amochi (Arisaema schimperianum Schott) in Ethiopia as revealed by AFLP markers

Amochi (Arisaema schimperianum Schott) is an off-season crop plant in southern Ethiopia, grown during the dry season on residual moisture, for its edible tubers. It has gained importance as a "security crop" especially during the years of moisture stress and food shortage. Amochi is irritating in contact to the skin. Removal of this effect is an important question for breeding. As the first step, however we attempt to establish base line information of its breeding system and genetic variability using AFLPs. The extent of genetic differentiation among 11 populations (96 individuals) of amochi sampled along altitudinal gradients that varied from 1700 to 3200 m a.s.l. was investigated. The populations were classified in to three altitudinal groups: lowland (1700 to 2200 m a.s.l.), central-highland (2201 to 2600 m a.s.l.) and highland (2601 to 3200 m a.s.l.). Polymorphic loci (167) scored from four primer pair combinations, were used for principal component analysis (PCA), and analysis of molecular variance (AMOVA). Both PCA and unweighed pair group with arithmetic mean (UPGMA) clearly differentiated populations into their respective altitude groups, with large genetic distances. AMOVA analysis revealed 70.5%, 16.7% and 12.8% variability between altitude groups, between populations and within populations respectively. Average diversity indices within populations were also low. Since the largest proportion of variation is located between altitude groups, rather than within populations, we suggest future studies on the chemical composition, low irritation, and other desirable traits should consider populations from different altitude ranges.

Modelling of transient moisture concentration of semolina pasta during air drying

The drying process for pasta is considered on an empirical basis in industrial applications. The results presented in this paper concern the theoretical and experimental data, obtained during the drying process of semolina pasta. The moisture concentration is modelled for durum semolina pasta by assuming the mass transfer between the pasta and the air. As the transport kinetics are entirely controlled by the internal transport resistance, Fick’s law applies. The moisture concentrations of durum pasta are predicted as a function of pasta properties (initial moisture concentration, thickness and food composition) and air properties (air temperature and relative humidity). The model was afterwards validated for different model inputs and the validation measurements correspond well with the experimental data. Finally a parameter study was performed to study the impact of the model parameters on the moisture concentration.

Components of Developmental Plasticity in a Michigan Population of &lt;I&gt;Lucilia sericata&lt;/I&gt; (Diptera: Calliphoridae)

Forensic entomologists rely on laboratory growth data to estimate the time of blow fly colonization on human remains. Several data sets exist for the development of the common blow fly Lucilia sericata (Meigen) (Diptera: Calliphoridae), and although they generally describe similar rates of preadult development, all vary. Such differences could be explained by genetic variation, environmental (rearing) variation, or both. In the study presented here, flies from a single population were reared under variable conditions of food moisture, substrate type, substrate freshness, and sampling, to determine the effect each had on developmental time. Cohorts were tested in a single incubator at a single temperature and humidity, to eliminate effects of undesired environmental variation. Fly developmental times were significantly influenced by multiple laboratory rearing treatments; food moisture, transferring postfeeding larvae to fresh substrate, and destructive sampling affected different stages of development. Developmental times ranged from 329 to 505.5 h, covering the spectrum of variation observed in published data sets. Growth was then compared with larval development on rat carcasses under the same environmental conditions, establishing a link between laboratory-controlled growth and development on carrion. Cohorts raised on rats matured to adulthood between 333 and 337 h, which was best mimicked by the fastest growth treatment observed under laboratory conditions. The large environmental influence on development observed in this study could affect forensic entomology casework and accentuates the need for a standardized means of rearing flies in a laboratory setting that is relevant to decomposition on a corpse.

Hydration Status in the United States and Germany

In the United States and Germany, population groups show distinct differences in water metabolism. A higher intake of preformed water (fluids and food moisture) and a higher urinary volume hint towards a more favorable hydration status of the American than the German population. In the United States, the Adequate Intake for preformed water is set based on the median preformed water intake from US survey data. In Germany, physiologically founded and empirically based Guiding Values are proposed. The recommended intake of preformed and metabolic water related to energy intake ranges from 1.01 to 1.08 mL/kcal in German adults and from 1.21 to 1.31 mL/kcal in American adults.

Catalase-based thin-layer enzyme cell used in organic-phase FIA system for determination of moisture in oily foods

The aim of our present work was to study the possibility of constructing a biosensor based on immobilized catalase enzyme (EC 1.11.1.6.) in organic-phase solutions. The catalase enzyme was immobilized by glutaraldehyde on a natural protein membrane in a thin-layer enzyme cell, connected to a stopped-flow injection analyser (SFIA) system with an amperometric detector. Adding FMCA to acetonitrile, the optimal concentration was 7.5 mg l−1, while with TBATS it was 2.7 mg l−1. The optimal pH value of the immobilized enzyme in buffer was about 6.0. On studying the role of the buffer solution used in the carrier solvent, the activity of the enzyme changed dramatically. The signal was highest when there was no buffer added to the carrier solution and decreased rapidly when the content increased (0–1.5%). Utilizing these results, a quick analytical method was developed to monitor indirectly the water content (activator) in various butter and margarine samples by maintaining a fixed substrate concentration. The water content of samples was compared with the results obtained by the gravimetric reference method (AOAC Method 920.116); the correlation coefficient (r) was 0.993.

Water turnover in 458 American adults 40-79 yr of age.

Despite recent interest in water intake, few data are available on water metabolism in adults. To determine the average and range of usual water intake, urine output, and total body water, we administered 2H oxide to 458 noninstitutionalized 40- to 79-yr-old adults living in temperate climates. Urine was collected in a subset of individuals (n = 280) to measure 24-h urine production using p-aminobenzoic acid to ensure complete collection. Preformed water intake was calculated from isotopic turnover and corrected for metabolic water and insensible water absorption from humidity. Preformed water intake, which is water from beverages and food moisture, averaged 3.0 l/day in men (range: 1.4-7.7 l/day) and 2.5 l/day in women (range: 1.2-4.6 l/day). Preformed water intake was lower in 70- to 79 (2.8 l/day)- than in 40- to 49-yr-old men and was lower in 70- to 79 (2.3 l/day)- than in 40- to 49- and 50- to 59-yr-old women. Urine production averaged 2.2 l/day in men (range: 0.6-4.9 l/day) and 2.2 l/day in women (0.9-6.0 l/day). There were no age-related differences in results in women, but 60- to 69-yr-old men had significantly higher urine output than 40- to 49- and 50- to 59-yr-old men. Only the 70- to 79-yr-old group included sufficient blacks for a racial analysis. Blacks in this age group showed significantly lower preformed water intake than did whites. Whites had significantly higher water turnover rates than blacks as well. Multivariate regression indicated that age, weight, height, and body mass index explained <12% of the gender-specific variance in water input or urine output, yet repeat measures indicated that within-individual coefficient of variation was 8% for preformed water intake (n = 22) and 9% for 24-h urine production (n = 222). These results demonstrate that water turnover is highly variable among individuals and that little of the variance is explained by anthropometric parameters.

Sample Matrix Interference in Immunoassays for Organochlorine Residues in Plant-derived Foods and Some Strategies for Their Removal

Immunoassays for two groups of organochlorine insecticides, cyclodienes (endosulfan and heptachlor) and DDT were applied to the analysis of a diverse range of plant-derived foods. Water-miscible solvent extracts of high-moisture, low-fat foods such as cauliflower, cabbage, green and red blue grapes and tomato caused little or no interference with the assays, enabling methanol or acetonitrile extracts of the foods to be analysed directly by immunoassay, after dilution in assay buffer. Reasonable recoveries of spikes of these pesticides were obtained by direct analysis of extracts of spiked commodities, with reliable detection down to 0.025 mg kg−1 heptachlor or endosulfan and 0.1 mg kg−1 DDT in the commodities. Acetonitrile extracts of milk could also be analysed directly for DDT. In contrast, extracts of low moisture, non-fatty (rice) and fatty (cottonseed) food commodities interfered appreciably with the assays, reducing assay colour and detection sensitivity. Some simple cleanup methods were developed to remove interference and enable detection of spiked organochlorines in these foods. Extracts of coloured foods, such as tea, coffee and spinach caused similarly major interference in the assays, and a number of simple clean-up methods were ineffective in removing interference. However, use of an immunoaffinity chromatography method for cyclodienes enabled quantitative recoveries to be obtained in extracts of several of these foods when analysed by either ELISA or gas chromatography. Direct analysis was suited for screening purposes but immunoaffinity chromatography results were more quantitative. These results indicate that ELISAs can be applied under developing country conditions to a range of diverse foods, but that cleanup strategies need to be tailored to different types of foods.