UVM Theses and Dissertations
Format:
Print
Author:
Rajbhandari, Pallavi
Dept./Program:
Nutritional and Food Sciences
Year:
2009
Degree:
PhD
Abstract:
Previous research demonstrated that crystal coverage on the surface of Cheddar cheese can be quantitatively and nondestructively measured using image analysis of digital photographs of the cheese surface. Image analysis can be used to measure the crystal formation rate which may be considered an indicator of the number of surface sites at which crystal nucleation occurred and also be used to evaluate crystal growth rates by measuring the increase in areas of individual discrete crystal regions (DCR) over time. Crystal growth on uncolored cheese was effectively quantified using the revised image analysis method.
Smoked Cheddar cheeses are vulnerable to crystal formation so to determine the cause of its susceptibility we analyzed smoked samples immediately after smoking process. The results indicate that calcium and lactate in'the serum phase of the cheese were elevated as a result of smoking, especially at the cheese surface immediately after smoking treatment, and this may predispose the cheeses to increased susceptibility to calcium lactate surface crystallization.
Post manufacture treatment conditions of storage temperature, pacakaging tighthness and surface roughness were studied. The results showed that the number of discrete crystal regions varied significantly during storage in a temperature dependent manner as follows: 5°C<1°/10°C<10°C<1°C. However, the total crystal area showed a slightly different trend as follows: 5°C<1°/10°C<1°C<10°C. Storage temperature did not appear to have a major effect on the growth rates and shapes of the individual crystals that were chosen for analysis. The data indicated that storage temperature had a complex mechanism that affected the number of crystal formation sites on the cheese surface and the total area of crystals on the cheese surface.
Loose packaging caused large, significant increases in the number of discrete crystals formed per unit of surface area and the total surface area occupied by crystals. However, packaging tightness did not appear to have a major effect on the growth rates or shapes of individual crystals that were chosen for analysis. The data indicate that loose packaging primarily increased the number of nucleation sites on the cheese surface that subsequently developed into discrete visible crystals. The combination of smooth surface plus very tight packaging virtually eliminated crystal formation by eliminating available sites for nucleation. The data suggest that the cut-and-wrap step in commercial Cheddar cheese production is a critical control point for crystal formation.
When cheeses were manufactured using different cheese milk composition and different manufacturing protocols, the milk formulation (non fortified versus fortified) significantly affected moisture, salt in moisture, pH and lactose. Ripening time significantly affected pH, lactose and total lactate in moisture. The levels of moisture, pH, salt in moisture, lactose, total lactate in moisture and water soluble calcium did not vary significantly with time over a ripening period of 16 wk for both non fortified and fortified cheeses.
Smoked Cheddar cheeses are vulnerable to crystal formation so to determine the cause of its susceptibility we analyzed smoked samples immediately after smoking process. The results indicate that calcium and lactate in'the serum phase of the cheese were elevated as a result of smoking, especially at the cheese surface immediately after smoking treatment, and this may predispose the cheeses to increased susceptibility to calcium lactate surface crystallization.
Post manufacture treatment conditions of storage temperature, pacakaging tighthness and surface roughness were studied. The results showed that the number of discrete crystal regions varied significantly during storage in a temperature dependent manner as follows: 5°C<1°/10°C<10°C<1°C. However, the total crystal area showed a slightly different trend as follows: 5°C<1°/10°C<1°C<10°C. Storage temperature did not appear to have a major effect on the growth rates and shapes of the individual crystals that were chosen for analysis. The data indicated that storage temperature had a complex mechanism that affected the number of crystal formation sites on the cheese surface and the total area of crystals on the cheese surface.
Loose packaging caused large, significant increases in the number of discrete crystals formed per unit of surface area and the total surface area occupied by crystals. However, packaging tightness did not appear to have a major effect on the growth rates or shapes of individual crystals that were chosen for analysis. The data indicate that loose packaging primarily increased the number of nucleation sites on the cheese surface that subsequently developed into discrete visible crystals. The combination of smooth surface plus very tight packaging virtually eliminated crystal formation by eliminating available sites for nucleation. The data suggest that the cut-and-wrap step in commercial Cheddar cheese production is a critical control point for crystal formation.
When cheeses were manufactured using different cheese milk composition and different manufacturing protocols, the milk formulation (non fortified versus fortified) significantly affected moisture, salt in moisture, pH and lactose. Ripening time significantly affected pH, lactose and total lactate in moisture. The levels of moisture, pH, salt in moisture, lactose, total lactate in moisture and water soluble calcium did not vary significantly with time over a ripening period of 16 wk for both non fortified and fortified cheeses.