scholarly journals Evaluation of physico-chemical characteristics of fresh, refrigerated and frozen Lacaune ewes' milk

2014 ◽  
Vol 66 (6) ◽  
pp. 1924-1930 ◽  
Author(s):  
L.W. Fava ◽  
I.C. Külkamp-Guerreiro ◽  
A.T. Pinto

The production of ewe milk is seasonal and milk yield per animal is low, even in specialized animals. This study aimed to verify the possibility of preserving bulk tank milk for seven days under cooling (5°C) and freezing (-5°C), verify the influence of cooling treatments and of the months of the year on the physical and chemical characteristics of the product. The chemical composition of milk, including the fat, protein, lactose and total solids contents, was not altered by cooling and freezing. Protein and lactose contents varied according to the months of the year. The average percentage and standard deviation of fat, protein, lactose and total solids was 8.10±1.30, 5.22±0.37, 4.43±0.23 and 19.34±1.54, respectively. The density, pH, titratable acidity, as well as alcohol and heat stability tests were significantly influenced by the treatments used (P < 0.05), but no differences were found between fresh and frozen milk. Prolonged refrigeration caused an increase in acidity and decrease in pH, with a consequent reduction in the stability of milk. These results demonstrated that freezing does not affect the chemical composition and physical characteristics of milk in nature and it could be a solution for the producer and the sheep milk industry.

Author(s):  
A. C. Honorato ◽  
C. B. R. Dias ◽  
E. B. Souza ◽  
I. R. B. Carvalho ◽  
K. S. M. Sousa

<p>Este trabalho teve como objetivo avaliar os parâmetros físico-químicos de polpas de fruta produzidas e comercializadas na cidade de Petrolina-PE, tendo como referência a Instrução Normativa nº 1, de 7 jan. 2000, do Ministério da Agricultura que define as características físicas e químicas estabelecendo limites mínimos e máximos específicos para cada polpa de fruta. Foram avaliadas duas marcas (1 e 2) de polpas de abacaxi, cacau, caju, graviola, maracujá e umbu, analisadas quanto aos parâmetros de pH, sólidos solúveis totais (SST), acidez total titulável (ATT), ácido ascórbico, relação SST/ATT e sólidos totais. Os resultados permitem inferir que a marca 2 apresentou qualidade superior na maioria dos parâmetros avaliados quando comparado com a marca 1. Entretanto para alguns sabores de polpa as duas marcas não atenderam os valores padrões. Entre as polpas o único sabor que apresentou os padrões exigidos foi a polpa de caju em ambas as marcas, e a que apresentou resultado de pior qualidade diante dos padrões foi a polpa de maracujá principalmente da marca 1. Dessa forma constata-se que há grandes variações entre as marcas, e entre alguns parâmetros, o que compromete a qualidade das polpas, prejudicando assim o consumidor.</p><p align="center"><strong><em>Physicochemical parameters of fruit pulps produced in Petrolina – PE</em></strong></p><p><strong>Abstract</strong><strong>: </strong>This study aimed to evaluate the physicochemical parameters of fruit pulps produced and marketed in the city of Petrolina-PE, with reference to the Instruction Nº 1 of 7 January 2000 of the Ministry of Agriculture, which defines the physical and chemical characteristics setting minimum and maximum limits specific to each fruit pulp. We evaluated two brands (1 and 2) of pineapple, cocoa, cashew, soursop, passion and umbu fruit pulp, analyzed for pH, total soluble solids (TSS), total titratable acidity (TTA), ascorbic acid, TSS / TTA and total solids parameters. Results show that the brand 2 showed superior in most evaluated parameters when compared to the brand 1. However, for some pulp flavors of both brands did not reached the standards values. Among the pulps, the only flavor that presented the required standards was the cashew pulp in both brands, and presented the results of lower quality on the standards was the passion fruit pulp mainly brand 1. Thus, it appears that there are great variations between brands and between some parameters, which compromises the quality of the pulp, thus impairing the consumer.</p>


1981 ◽  
Vol 48 (1) ◽  
pp. 123-129 ◽  
Author(s):  
Douglas B. Hyslop ◽  
Patrick F. Fox

SummaryAs determined by the standard subjective assay procedure, the minimum in the heat stability–pH curve of milk persisted down to at least 116 °C. However when samples were not agitated during heating the minimum became progressively less pronounced as the assay temperature was lowered and it disappeared at approximately 116 °C. Activation energies (Ea) for unagitated samples were approximately 30 Kcal/mole at pH 6·87 (maximum) and at pH 7·18, throughout the temperature range 116–145 °C and for the pH 6·95 (minimum) sample at 116–125 °C; however Eα for the pH 6.95 sample increased to approximately 100 Kcal/mole in the range 127–135 °C suggesting that some highly temperature-dependent reaction had occurred and caused premature coagulation at certain pH values, i.e. to a heat stability minimum. The stability of concentrated milk (20% total solids) was very low at pH values above 6·9, regardless of whether the samples were agitated or not during heating and the maximum/minimum in the heat stability–pH curve persisted down to at least 90 °C in both agitated and quiescent samples.


2014 ◽  
Vol 54 (8) ◽  
pp. 1091 ◽  
Author(s):  
Razzagh Mahmoudi ◽  
Reza Norian ◽  
Mohammad Reza Pajohi-Alamoti ◽  
Javad Aliakbarlu

The quality and hygienic status of milk are of importance for both dairy industries and consumers. In the present study, the effect of season on the quality and microbial properties of sheep milk and yoghurt produced from sheep milk were surveyed. In total, 30 sheep-milk samples were collected from January to August 2011, and yoghurt was produced from these samples. The fat content, titratable acidity and pH showed changes across the year. Seasonal variation was found to have a significant (P < 0.05) effect on nitrogen components, particularly crude protein, non-casein protein and non-protein nitrogen contents, fat content, pH and titratable acidity. Sensory analysis showed that the quality of yoghurt samples produced in winter was higher than that of yoghurt produced in summer (P < 0.05). This work showed the effect of season on chemical and sensory properties of sheep milk and yoghurt in Qazvin, Iran.


2018 ◽  
Vol 277 ◽  
pp. 80-89 ◽  
Author(s):  
Zynovii Malanchuk ◽  
Viktor Moshynskyi ◽  
Yevhenii Malanchuk ◽  
Valerii Korniienko

Amber of amber-bearing deposits in Rivne-Volyn region of Ukraine has been analyzed. Relying upon instrumental techniques, physical and chemical as well as spectral analyses, and geological prospecting of the deposits, chemical composition and ultimate composition of amber occurring at the territory of Klesiv deposit (Ukraine, Rivne Region, Sarny District) have been identified. Klesiv amber contains the greatest part of inclusions; it contains 18 chemical elements. Basing upon the performed geological cross-section it has been determined that the amber occur in sandy soil and sandy-shale soil. The depth is insignificant – from 1 m to 10 – 15 m. Moreover, to determine the cost, experimental technique has been developed. The technique involves classification of the amber fragments according to their form, dimensions, and colour. Lithologic-and-facies sections of sites of Klesiv deposit have been obtained.


2016 ◽  
Vol 29 (1) ◽  
pp. 246-256
Author(s):  
EMANUEL NETO ALVES DE OLIVEIRA ◽  
DYEGO DA COSTA SANTOS ◽  
YVANA MARIA GOMES DOS SANTOS ◽  
PAULO RENATO BUCHWEITZ ◽  
JOSIVANDA PALMEIRA GOMES

ABSTRACT: Soursop is a well-appreciated tropical fruit, both in natura and in the form of juices and nectars. Despite its wide acceptance, there is lack of its use in the preparation of other products, such as alcoholic beverages. The objective of this study was to prepare soursop liquors by varying the concentrations of pulp and sucrose syrup with different contents of total soluble solids and to evaluate the effects of these on the physical and chemical characteristics of the beverages. In the production process, the pulp (300, 400 and 500 g) was macerated with distilled alcohol for 20 days, after which it was filtered, added to the syrup (50, 60 and 70 °Brix), bottled in polyethylene bottles and subjected to an accelerated aging. All drinks resulted in alcohol levels (15.25 to 16.69% v/v) and total sugars (12.63 to 17.97%) in accordance with the standards required by law. The experiments made with the lowest concentration of pulp showed the highest yields (84.17 and 85.25%). First-order models with interactions and 95% confidence intervals were obtained. The pulp consisted of the most significant factor, influencing the largest number of responses (yield, alcohol content, dry residue, titratable acidity, titratable acidity/soluble solids ratio and luminosity). The larger coefficient of determination (R2) values were found in the models adjusted to the data of yield, dry residue, total soluble solids, titratable acidity and total sugars, which were significant and predictive, showing values greater than 0.97.


2015 ◽  
Vol 67 (6) ◽  
pp. 1735-1742
Author(s):  
E.H.P. Andrade ◽  
N.M.A. Silva ◽  
M.F.S. Resende ◽  
M.R. Souza ◽  
L.M. Fonseca ◽  
...  

This study aimed to evaluate some microbiological and physical-chemical characteristics of fermented milk beverages collected at the main supermarkets in Belo Horizonte (MG). 40 samples of the products corresponding to five distinct brands were collected. They were submitted to the following analyses: Most Probable Number (MPN) of total (30ºC) and thermal tolerant coliforms (45ºC), Salmonella spp., coagulase positive Staphylococcus, molds and yeasts, lactic acid bacteria, pH, titratable acidity and contents of moisture, total solids, protein and fat. The analyses were carried out during the last week of shelf life. The microbiological quality of the samples was good and the counts of lactic bacteria were above the minimum established by the official legislation. Streptococcus and Lactobacillus were isolated and identified from the products and Lactobacillus delbrueckii was molecularly identified in three samples. The mean values for the contents of fat and protein, titratable acidity, pH, moisture and total solids ranged from 1.24 to 1.98%; 1.88 to 2.22%; 0.54 to 0.66%; 3.91 to 4.16; 81.18 to 83.25% and 16.75 to 18.82%, respectively. All samples had protein content in agreement with the official legislation.


1990 ◽  
Vol 57 (1) ◽  
pp. 41-51 ◽  
Author(s):  
Leandros Voutsinas ◽  
Christophoros Pappas ◽  
Maria Katsiari

SummaryVariations in chemical composition and in some physico-chemical properties of milk from a herd of lactating Alpine goats imported into Greece were determined from week 8 after parturition until the end of lactation (35 weeks, 35 samples). The average composition (g/100 g) of the milk was: fat 3·44, protein 3·35, casein 2·46, lactose 4·30, ash 0·79, total solids 11·76 and solids-not-fat 8·32. The average pH was 6·57 and titratable acidity was 16·76 (°D). The averaged density was 1·030. The mean mineral contents (mg/100 g) of the milk were: Na 53·12, K 157·67, Ca 140·06, P 110·00, Mg 13·59, citrate 106·97. All constituents studied as well as pH and density were significantly (P < 0·05) dependent on the stage of lactation. Titratable acidity was not significantly affected by stages of lactation. There were significant (P < 0·001) differences in Na/K and Ca/P ratios in the milk between lactation stages. Trends with lactation for each of the components and physico-chemical properties determined are reported and correlations between constituents in the milk are given.


Author(s):  
C. A. Paiva ◽  
E. M. M. Aroucha ◽  
R. M. A. Ferreira ◽  
N. O. Araújo ◽  
P. S. L. Silva

<p>O processamento de polpa e a fabricação de geleias são produtos de interesse para a região nordeste do Brasil. A baixa precipitação e os altos índices de luminosidade anuais, associado ao desenvolvimento da irrigação localizada na região, atraíram grandes empresas nacionais e internacionais para a produção de variados tipos de frutos, incluindo a acerola e o melão. O objetivo do presente trabalho foi avaliar as características físico-químicas de geleia simples e mista (50% de melão e 50% de acerola) de melão e acerola, por ocasião do preparo e após o armazenamento por 30 dias. Utilizou-se o delineamento inteiramente casualizado. O tempo de armazenamento aumentou o teor de sólidos solúveis (SS) e o pH, mas reduziu a acidez titulável e o teor de ácido ascórbico das geleias. A geleia de melão apresentou o maior teor de SS após o armazenamento. E a geleia de acerola obteve valores superiores de pH, acidez titulável e vitamina C, nas duas épocas de análise. Já a geleia mista apresentou pH igual à geleia de melão, mas quanto às demais características situou-se entre às geleias simples.</p><p align="center"><strong><em>Physical and chemical characteristics of acerola and melon jellies during storage</em></strong></p><p><strong>Abstract: </strong>The pulp processing and the manufacture of jellies are products of interest to the northeastern region of Brazil. The low rainfall and high rates of annual luminosity associated with the development of drip irrigation in the region, attracted large national and international companies for the production of various kinds of fruits, including acerola and melon. The objective of this study was to evaluate the physico-chemical characteristics of single and mixed jelly (50% of melon and 50% acerola) of melon and acerola, on the occasion of preparation and after storage for 30 days. We used a completely randomized design. The storage time increased the soluble solids (SS) and pH, but reduced titratable acidity and ascorbic acid content from jelly. The melon jelly had the highest SS content after storage. And acerola jelly obtained higher values of pH, titratable acidity and vitamin C, in two periods of analysis. However the mixed jelly showed pH seems to jelly melon, but to the other features it was between the simple jelly.</p>


2015 ◽  
Vol 6 (1) ◽  
pp. 51
Author(s):  
Juliana Angelo Pires ◽  
Aline Da Silva Delabio ◽  
Rafaela Prezotto Vicente ◽  
Marcia Nalesso Costa Harder ◽  
Lucia Cristina Aparecida Santos Silva ◽  
...  

<p>The current study deals with <em>cacha&ccedil;a</em> irradiation in the presences of grapes, with the use of gamma radiation (Co 60) to evaluate its effects on the physical and chemical characteristics of this beverage. The research had as objective to assess the effects of irradiation in <em>cacha&ccedil;as</em>, in the extraction of compounds present in the pickled grapes in the <em>cacha&ccedil;a</em>. Samples were prepared with grapes type Crimson, in polypropylene bottles, with and without grapes. Both types of samples were irradiated with doses of 0 (control) and 300Gy. Later were performed physical and chemical analyzes (pH, titratable acidity, soluble solids) during a 5-day span after irradiation treatment. Significative statistical difference was noticed in titratable acidity of the samples that contained grapes, larger values when compared with pure samples. However, there was no statistical difference when comparing the pure beverage with control or the beverage containing grapes and control. For pH the values for the samples with grapes is statistically lower than the others. The results for soluble solids (&ordm;Brix) displayed an increase on both types of samples comparing with their respective controls. In conclusion, the 300Gy dose was effective for increasing soluble solids quantity both in pure <em>cacha&ccedil;as</em> as in presences of grapes. Relating to pH and acidity, this dose shows interference when grapes are presents.</p><p>&nbsp;</p><p>DOI: 10.14685/rebrapa.v6i1.199</p>


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