scholarly journals Determination of Chemical Composition of Plums During Pre-Treatment and Drying

2012 ◽  
Vol 19 (1) ◽  
pp. 89-96 ◽  
Author(s):  
Dorota Walkowiak-Tomczak

Determination of Chemical Composition of Plums During Pre-Treatment and DryingThanks to drying, fruits are available on the market throughout the year. Parameters of drying conditions affect eg the content of bioactive compounds in the product. The aim of the study was to investigate the effect of pretreatment conditions and the applied drying method on changes in the chemical composition of plums. Analyses were conducted on plums cv. 'Valor', which were subjected to pre-treatment including blanching, drilling and osmotic dehydration. Next they were dried by the convection method at air temperature of 60°C and flow rate of 1.5 m/s. Dehydration was run in a 61.5% sucrose solution at a temperature of 50°C for 1 or 2 h. Convection-dried plums, with no osmotic dehydration applied, constituted the reference sample. In fresh, dehydrated and dried fruits determinations included dry matter, polyphenols by colorimetry with the Folin reagent and contents of sugars by colorimetry using 3,5-DNS acid. As a result of blanching and dehydration the content of dry matter increased. Water loss after dehydration amounted to as much as 1.45 g H2O/g d.m.0after 2 h in comparison with blanched plums. As a result of dehydration total contents of sugars and polyphenols in plums decreased (mg/100 g d.m.). In convection-dried prunes the content of polyphenols was by 30÷50% higher than in the raw material, but lower than in the reference sample.

2016 ◽  
Vol 12 (6) ◽  
pp. 515-525 ◽  
Author(s):  
N. Ghanem Romdhane ◽  
N. Djendoubi ◽  
C. Bonazzi ◽  
N. Kechaou ◽  
N. Boudhrioua Mihoubi

Abstract Combined osmotic dehydration (sucrose solution: 50–70 % w/w, 30–50 °C for 2 h followed by air drying at 40 and 60 °C) is an appropriate process for preservation of oil retention capacity, lightness and yellowness of lemon peels (Citrus limon. v. lunari). Incorporation of sugars to lemon cuboids pieces increased drying rate during the first falling rate phase of the air dehydration step and improved their color stability. Osmotic dehydration process allows protective effect against further total phenol loss during air drying: significant loss of total phenol content (70–80 %) was recorded during osmotic dehydration and then it remains constant during air drying at 40 and 60 °C. For the investigated temperature of osmotic pre-treatment (30–50 °C), water retention capacities were reduced by up to 70 % and were maintained constant during air drying.


Fisheries ◽  
2020 ◽  
Vol 2020 (2) ◽  
pp. 113-117
Author(s):  
Olga Mezenova ◽  
Vladimir Wolkov ◽  
Larisa Baydalinova ◽  
Natalia Mezenova ◽  
Svetlana Agafonova ◽  
...  

The authors study three fractions obtained as a result of hydrolysis of smoked sprat heads (under temperature of 130oC and presser of 0.25 MPa) – fat, protein water-soluble, and protein-and-mineral ones. Waste from sprat production of two fish canning complexes of the Kaliningrad Region - “RosCon” and “Kolkhoz for the Motherland” - was used as raw material. Hydrolysis was carried out in an aqueous medium in two ways - with preliminary separation of fat and without this operation. The protein fraction was sublimated and its quantitative and qualitative indices were examined - mass yield, solubility, chemical composition and molecular fractional composition of the obtained peptide fractions were determined. The output of sublimated protein fractions is practically independent of the type of raw material and the method of pre-treatment and is 6.47.9% of the mass of raw materials. The chemical composition of protein fractions varies widely in terms of fat (1.4–8.3%), minerals (9.8–13.4%) and proteins (72.1–80.2%). The solubility of the peptide fractions ranged from 91-98%. The molecular weight assessment results showed a high content of a low molecular weight fraction of peptides with an MM of less than 10 kDa in all experimental samples (about 38%). This indicates a high digestibility and biological value of the obtained peptide compositions. Sublimated peptide compositions had typical organoleptic characteristics, pleasant aroma and taste of smoked fish. Ключевые


1970 ◽  
Vol 75 (2) ◽  
pp. 213-222 ◽  
Author(s):  
K. R. Christian ◽  
D. B. Jones ◽  
M. Freer

SUMMARYBulk harvests of primary growth were made at intervals during the spring and summer of 2 consecutive years from an ungrazed area of lucerne (Medicago sativa) and the digestibility by sheep was measured. At the same times, shoots of known length representative of the sward were collected, divided into 7·5 cm lengths, and separated into leaf and stem for the determination of ash, nitrogen, cellulose, and in vitro organic matter digestibility.Digestibility and leaf: stem ratio of the bulk harvests decreased and dry matter increased as the season advanced. Leaf composition changed little, but stem increased in lignin and decreased in ash and in vitro digestibility. In vitro digestibility and leaf: stem ratio were highly correlated with sheep digestibility.Chemical composition of shoots of known heights was similar to that of the bulk harvests. Leaf weights/shoot tended to increase linearly with height of shoot, whereas stem increased nearly as the square of the height. Dry matter of leaf and stem were inversely related to leaf:stem ratio. Stem digestibility decreased with leaf:stem ratio and with increase in shoot height.Chemical components of shoot fractions were associated with each other and were largely dependent on the distance from the top of the shoot at which they had been taken, irrespective of shoot height or time of year. Bottom stems had lower ash, nitrogen and digestibility but higher cellulose, dry weight and dry matter than top stems, whose composition approached that of leaves. Leaf fractions showed little consistent trend with position on the shoot.Some of the difficulties in studying changes in plant composition under field conditions are discussed.


Author(s):  
Nizamettin Turan

Research was conducted to determine the quality and chemical composition of silages obtained by mixing in different ratios of narbonne vetch (Vicia narbonensis L.) and barley (Hordeum vulgare L.) grown in rabi season of 2017-2018 in Eastern Anatolia, Turkey. In the study we studied the pure sowings of barley and narbonne vetch and their mixtures (20, 30, 40, 50, 60, 70, 80% of narbonne vetch (N) + 80, 70, 60, 50, 40, 30, 20% of barley (B). The values of ADF (acid detergent fiber), NDF (neutral detergent fiber), DDM (digestible dry matter), DMI (dry matter intake), DM (dry matter), CP (crude protein) and RFV (relative feed value) of silages of analyzed were respectively 33.38, 33.73, 62.89, 3.57, 24.69, 15.50%, 174.64. We also founded that LA (lactic acid), AA (acetic acid), BA (butyric acid), PA (propionic acid) and Ca, P, Mg, K and pH of silages investigated were respectively 1.60, 0.57, 0.42, 0.06, 1.17, 0.53, 0.25, 3.51% and 3.80. Our results shows that silages with high narbonne vetch were higher quality values for CP, ADF, NDF, DM, RFV, DDM, DMI, Ca, Mg, LA which determined chemical composition and feeding quality of silages. As a result, it is suggested that mixture silages with narbonne vetch (80%) and the barley ratio (20%) have important advantages for some properties of silages.


Author(s):  
Joanna Cichowska ◽  
Hanna Kowalska

AbstractThe cylinders of apples cv.Braeburnwere subjected to osmotic dehydration in a sucrose solution with the addition of chokeberry juice concentrate. After osmotic pre-treatment the pieces of apples were dried by two methods: freeze-drying and air-drying. The storage results of dried apples at temperature 25–45 °C for 7 and 12 months were satisfactory. Mass changes were very minor. During storage dried apples obtained by both methods exhibited microbiological stability even after 7 and 12 months of storage, due to the fact that the water activity did not exceed the value of 0.4. Under the influence of the technological processes application, as well as storage conditions, appearance changes in the samples occurred. Higher temperature of storage had an increase impact in colour changes of control samples (without osmotic pre-treatment) and also osmotically dehydrated into sucrose solution, mainly in the case of samples which had dried using freeze-drying. Previously immersed in chokeberry juice concentrate, dried apples had colour changes comes from colour of solution.


1952 ◽  
Vol 42 (3) ◽  
pp. 314-321 ◽  
Author(s):  
R. Waite ◽  
W. Holmes ◽  
J. Boyd

1. The experiments started in 1949 to determine the weight and chemical composition of the herbage dry matter eaten by two groups of dairy cows grazing under a rotational and a close-folding system of management have been continued in 1950.2. Good-quality herbage was fed in adequate quantity to both groups for 20 weeks, in four fiveweekly periods allowing a double change-over system for the groups. The weights of protein, fibre, other extractives, lignin and minerals eaten daily by the close-folded group were determined. Difficulty in obtaining truly representative herbage samples from the rotational paddock made such detailed analyses for the rotationally grazed cattle not worth while.3. The weight of dry matter eaten by the closefolded cows was remarkably constant, the mean was 26 lb./cow/day and the standard deviation ±2·7 lb. The weight eaten by the rotationally grazed cows was more difficult to measure and appeared to vary considerably, the average being 31 lb. dry matter/ cow/day, and the standard deviation ±3·1 lb. Reasons are suggested why this figure of 31 lb. may be at least 5% too high.4. The relationship between the chemical composition of herbage as cut for sampling and the probable composition of the herbage as eaten by the grazing animal is discussed. Correction curves are given to convert the protein and fibre contents of herbage as cut in these experiments to values corresponding to those in the herbage as eaten.5. An attempt has been made to provide a balance sheet, in terms of D.C.P. and S.E., of animal production against nutrient intake. A deficiency of both protein and energy existed during the first spring period in both 1949 and 1950 (according to presentday standards), and although the protein balance became positive later in the season, the energy provided by the grass eaten was still barely adequate.6. Mineral balances calculated for the closefolded cows showed deficiencies of both calcium and phosphorus during the period of high milk yield, with the balances becoming positive later in the grazing season.


Forests ◽  
2021 ◽  
Vol 12 (12) ◽  
pp. 1649
Author(s):  
Túlio Anselmo Sacramento Vieira ◽  
Taiana Guimarães Arriel ◽  
Antônio José Vinha Zanuncio ◽  
Amélia Guimarães Carvalho ◽  
Monique Branco-Vieira ◽  
...  

The chemical composition of wood is important to assess the quality of this raw material for the industry of cellulosic pulp production. The purpose of this work was to determine the chemical composition of Eucalyptus spp. grown for cellulosic pulp production. Ten Eucalyptus spp. clones with six years of age, located in the municipality of Itamarandiba, Minas Gerais, Brazil, were used. Quantification was obtained for extractives, monosaccharides, uronic acids, acetates, lignin, ash and the phenolic composition of the extracts. In average, clones showed around 2.7% extractives, with a predominance of polar compounds soluble in ethanol and water; 27.7% lignin and 0.3% ash. Glucose was the main sugar detected (64.2%), followed by xylose (19.3%). The main components of the extractives were steroids, fatty acids and aromatic acids, followed by smaller amounts of substituted alkanoic acids, fatty alcohols, glycerol derivatives and triterpenes. The ethanol–water extracts presented total phenol contents ranging from 321.4 to 586.6 mg EAG/g of extract, tannins from 28.1 to 65.1 mg catechin/g of extract and flavonoids from 73.6 to 256.9 mg catechin/g of extract. Clones with a higher holocellulose amount and a lower lignin content showed a higher potential for cellulosic pulp production. These findings are important for the development of high-quality wood based on important traits for the pulp and paper sector.


Food Research ◽  
2020 ◽  
Vol 4 (4) ◽  
pp. 1140-1150
Author(s):  
G. Lentzou ◽  
Ch. Templalexis ◽  
G. Xanthopoulos

Sea buckthorn is ranked among the most significant super foods worldwide. Its fruits and leaves are used as fresh or dried in food, pharmaceutical and cosmetic industry. As super food any pre-treatment should sustain this property and hence this research was focused on osmotic dehydration of sea buckthorn by stevia also a super food. Therefore, water loss, sugar gain, acidity, ascorbic acid and water diffusivity were evaluated during osmotic dehydration of sea buckthorn by two stevia solutions, 15ο and 30οBrix and following were air-dried at 50οC by comparing the effect of steam blanching per case. Steam blanched samples exhibited increased water loss at the end of the process, 55% at 30οBrix and 48% at 15οBrix, compared to untreated samples where losses were 43% (30οBrix) and 28% (15οBrix) respectively. Ascorbic acid was significantly reduced, exceeding 50% in steam blanched samples and 23% in untreated samples. Steam blanched samples dehydrated at 15oBrix exhibited 82% dry matter increase and only 39% the untreated samples. Similarly, samples dehydrated at 30oBrix exhibited 84% dry matter increase and 53% when no steam blanching was applied. Solid gain was seven times less compared to water loss which is attributed to high molecular weight of steviol glycoside. The osmotic dehydration and airdrying curves were described effectively by Peleg and Fick models, and Logarithmic and Fick models respectively, having in all cases R2 adj>99% and SEE<0.2. The water diffusivity of steam blanched samples was 3.2-5.57×10-11 m 2 /s for water loss and 1.27- 2.03×10-11 m 2 /s for solid gain at 30oBrix and 2.12-4.27×10-11 m 2 /s and 0.91-1.98×10-11 m 2 /s at 15oBrix. Finally, the water diffusivity of steam blanched samples during air-drying was 2.11-2.29×10-11 m 2 /s and 1.56-1.66×10-11 m 2 /s in the case of untreated samples.


2021 ◽  
Vol 15 (4) ◽  
pp. 559-566
Author(s):  
Vahab Ghalandari ◽  
◽  
Hamidreza Bagheri ◽  
Ali Mohebbi ◽  
Hadi Esmaeili ◽  
...  

In this study, the effect of chemical composition of the raw material on the clinker burnability was studied by determination of free CaO (wt %) content of clinker. The burnability of two types of Portland clinker was investigated for silica modules of 2.3, 2.5 and 2.7 and lime saturation factor of 0.88–0.98. In addition, using the Multi-gene genetic programming (MGGP) model, the burnability of clinker was predicted. The results of MGGP model indicated that the performance of the model for predicting the amount of free CaO (wt %) was acceptable. Moreover, using MGGP, a promising correlation was introduced for accurately calculating the amount of free CaO (wt %). The performance of this correlation was compared with FL-Smidth, and it was established that the average errors of MGGP correlation and FL-Smidth equation were 2.95 and 7.45 %, respectively.


Minerals ◽  
2020 ◽  
Vol 10 (8) ◽  
pp. 654 ◽  
Author(s):  
Päivi Kinnunen ◽  
Jarno Mäkinen ◽  
Marja Salo ◽  
Ratana Soth ◽  
Konstantinos Komnitsas

Copper slags produced in vast quantities in smelting operations could be considered as secondary material sources instead of stockpiling them in landfills. This study investigates the recovery of valuable metals from copper slag and the valorisation of the leach residue as construction material in line with the principles of a circular economy. By taking into account that the environmental characterization of the as-received copper slag did not allow its disposal in landfills without prior treatment, chemical and biological leaching were tested for the recovery of metals. Pre-treatment with acids, namely HNO3 and H2SO4, resulted in the extraction of several target metals and the production of an almost inert waste. Despite the clearly better oxidative conditions prevailing in the bioleaching reactors, chemical leaching resulted in the higher dissolution of Cu (71% vs. 51%), Co (70% vs. 36%), and Zn (65% vs. 44%). The acid consumption was much lower during the bioleaching experiments compared to the chemical leaching. The bioleach residue was suitable for its use as supplementary cementitious material, showing a better performance than the reference sample without causing any detrimental effects to the calcium aluminate cement (CAC) quality. The complete valorisation of copper slags is expected to improve the economics of the process, by avoiding landfill costs and producing saleable products with high added value.


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