1,720,989 research outputs found
Quantification of Cheese Yield Reduction in Manufacturing Parmigiano Reggiano from Milk with Non-Compliant Somatic Cells Count
Full text linkThe mammary gland inflammation process is responsible for an increased number of somatic cells in milk, and transfers into the milk of some blood components; this causes alterations in the chemical composition and physico-chemical properties of milk. For this reason, somatic cell count (SCC) is one of the most important parameters of milk quality; therefore, European Union (EU) Regulation no 853/2004 has stated that it must not exceed the limit value of 400,000 cells/mL. The research aimed to compare chemical composition, cheese yield, and cheesemaking losses of two groups of vat milks used for Parmigiano Reggiano production, characterized by different SCC levels. During two years, ten cheesemaking trials were performed in ten different cheese factories. In each trial, two cheesemaking processes were conducted in parallel: one with low SCC milk (below 400,000 cells/mL; Low Cell Count (LCC)) and the other with high SCC milk (400,000–1,000,000 cells/mL; High Cell Count (HCC)). For each trial, vat milk and cooked whey were analyzed; after 24 months of ripening, cheeses were weighed to calculate cheese yield. The HCC group had lower casein content (2.43 vs. 2.57 g/100 g; p ≤ 0.05) and number (77.03% vs. 77.80%; p ≤ 0.05), lower phosphorus (88.37 vs. 92.46 mg/100g; p ≤ 0.05) and titratable acidity (3.16 vs. 3.34 °SH/50 mL; p ≤ 0.05) compared to LCC. However, chloride (111.88 vs. 104.12 mg/100 g; p ≤ 0.05) and pH (6.77 vs. 6.71; p ≤ 0.05) were higher. Fat losses during cheesemaking were higher (20.16 vs. 16.13%). After 24 months of ripening, cheese yield was 8.79% lower for HCC milk than LCC (6.74 vs. 7.39 kg/100 kg; p ≤ 0.05)
Chemical composition, hygiene characteristics, and coagulation aptitude of milk for Parmigiano Reggiano cheese from herds yielding different milk levels.
No full textThe objective with this research was to compare milk quality parameters among herds characterized by different levels of milk production. The research involved 1080 bulk milk samples collected from 30 dairy herds, which produce milk for Parmigiano Reggiano cheese, during three years. Each milk sample was analysed for fat, crude protein, titratable acidity, total bacterial count, somatic cells, coliform bacteria, and Clostridia spores. Least mean values were obtained by ANOVA using milk production intervals from 6000 to 7999 (L-group), from 8000 to 9999 (M-group), and from 10000 to 12000 kg/cow/lactation (H-group) as fixed milk production classes. Increased milk production was associated with a reduction in milk fat content (from 3.54 in the L-group milk to 3.29 g/100 g in the H-group milk). An improvement in the hygienic-sanitary quality of milk was observed with increasing milk production. In fact, a progressive decrease in the total bacterial count (from 95 in the L-group milk to 45 103 cfu/mL in the H-group milk), number of coliforms (from 2294 in the L-group milk to 1342 cfu/mL in the H-group milk), and somatic cell number (from 382 in the L-group milk to 209 103 cells/mL in the H-group milk) was observed with the increase in milk production level. Finally, it appears that higher milk yield is connected with significant positive effects on the lactodynamometric properties of milk
Effects of milk storage temperature at the farm on the characteristics of Parmigiano Reggiano cheese: chemical composition and proteolysis.
Full text linkParmigiano Reggiano is a Protected Designation of Origin (PDO) cheese whose official production protocol provides that milk cannot be stored at less than 18 °C at the farm. The possibility of refrigerating milk at the farm is highly debated, since it should allow for the limiting of bacterial growth, thus improving the quality of the cheese. The present research aimed to study the influence of storing the milk at 9 °C on the chemical composition and proteolysis during the ripening of Parmigiano Reggiano cheese. The experimentation considered six cheese-making trials, in which both evening and morning milks were subdivided into two parts that were maintained at 9 and 20 °C. After Parmigiano Reggiano cheese-making, one of the twin wheels obtained was analyzed after 21 months of ripening. From each cheese, two different samples were taken, one from the inner zone, and the other from the outer zone. The results of the chemical analyses evidenced that milk storage at 9 °C significantly (p ≤ 0.05) influenced fat, crude protein, soluble nitrogen and peptone nitrogen contents. Nevertheless, the differences observed with respect to the cheese obtained with milk stored under standard condition were very small and should be considered within the “normal variations” of Parmigiano Reggiano chemical characteristics
Proteose-peptone content of Italian Friesian herd milk produced in two different periods of the year.
No full textQuantification of the effect of the cattle breed on milk cheese yield: comparison between Italian Brown Swiss and Italian Friesian.
Full text linkCasein, phosphorus, urea and coagulation properties of Friesian herd milk characterised by low acidity.
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Going Beyond Counting First Authors in Author Co-citation Analysis
Full text linkThe present study examines one of the fundamental aspects of author co-citation analysis (ACA) - the way co-citation
counts are defined. Co-citation counting provides the data on which all subsequent statistical analyses and mappings
are based, and we compare ACA results based on two different types of co-citation counting - the traditional type that
only counts the first one among a cited work's authors on the one hand and a non-traditional type that takes into
account the first 5 authors of a cited work on the other hand. Results indicate that the picture produced through this non-traditional author co-citation counting contains more coherent author groups and is therefore considerably clearer. However, this picture represents fewer specialties in the research field being studied than that produced through the traditional first-author co-citation counting when the same number of top-ranked authors is selected and analyzed. Reasons for these effects are discussed
Distribution of Calcium, Phosphorus and Magnesium in Yak (Bos grunniens) Milk from the Qinghai Plateau in China
No full textThis research was aimed to assess the distribution of calcium, phosphorus and magnesium within the casein micelles of yak milk. To this aim, nine bulk yak milk samples (Y-milk), collected in three yak farms located in the Chinese province of Qinghai, were compared to nine bulk cow milk samples used as a reference. A quite similar content of colloidal calcium (0.80 vs. 0.77 mmol/g of casein; p > 0.05), a higher content of magnesium (0.05 vs. 0.04 mmol/g of casein; p = 0.01) and a lower content of colloidal phosphorus (0.48 vs. 0.56 mmol/g of casein; p = 0.01) between yak and cow casein micelles were found. Moreover, the yak casein micelles showed a lower value of prosthetic phosphorus (0.20 vs. 0.26 mmol/g of casein; p < 0.05) compared to the cow micelles. The lower values of colloidal and prosthetic phosphorus in yak casein micelles suggest that the yak casein is less phosphorylated than the cow one
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