Spatial variability in fundamental material parameters of Gouda cheese

Ripening of Nostrano Valtrompia PDO Cheese in Different Storage Conditions: Influence on Chemical, Physical and Sensory Properties

Nostrano Valtrompia is a hard, long-ripened, Italian Protected Designation of Origin (PDO) cheese typically produced by applying traditional cheesemaking practices in small dairies. Due to the limited production, this cheese is characterized by an important market price. Nostrano Valtrompia physico-chemical and sensory quality can be influenced by the duration and conditions of ripening. The objectives of this work were to characterize the physico-chemical and sensory characteristics of Nostrano Valtrompia cheese ripened for 12 and 16 months and to study the influence of different ripening warehouses: a temperature conditioned warehouse (TCW) and in a traditional, not conditioned warehouse (TNCW). The moisture gradient from the rind to the center of the cheese influenced texture, moisture, aw and color. Ripening in different warehouses did not affect the overall appreciation of the cheese nor other physico-chemical (color, moisture) or sensory traits. TCW cheeses were characterized by a slightly softer texture, slightly different openings distribution, and a different sensory perception than TNCW cheeses. These minor differences were related to the less variable environmental ripening conditions of TCW than TNCW. The results of this study can be useful to support the management of the ripening conditions of Nostrano Valtrompia PDO cheese and to rationally introduce new, suitable ripening sites.

Spatiotemporal Characterization of Texture of Crescenza Cheese, a Soft Fresh Italian Cheese

Crescenza cheese is a soft fresh cheese without rind, typically manufactured using a high amount of rennet. It is characterized by a fast proteolysis that causes changes in texture and leads to the so-called defect of “colatura” that is the tendency of the matrix to freely flow in the outer part of the cheese and generate spatial inhomogeneities into the cheese. In this paper, the textural properties of Crescenza were evaluated for cheeses manufactured using two types of rennet and starter cultures. Cheese texture was monitored during a 3-week shelf life considering a possible spatial variability of the matrix. At the beginning of the shelf life, a certain spatial inhomogeneity was observed from the center to the edge of the cheese block for all the trials. The firmness decreases from the center to the outer part of the block. During storage, hardness showed a decrease during 1st wk of storage; moreover, from days 7 to 21, cheese increased its hardness in the center and decreased it in the outer part of the block, resulting in a higher spatial inhomogeneity of the cheese. The textural measurements can be a useful tool to define the quality of Crescenza cheese during shelf life.

Biogenic amine production by Lactococcus lactis subsp. cremoris strains in the model system of Dutch-type cheese

The aim of this study was to compare the biogenic amine production of two starter strains of Lactococcus lactis subsp. cremoris (strains from the Culture Collection of Dairy Microorganisms - CCDM 824 and CCDM 946) with decarboxylase positive activity in a model system of Dutch-type cheese during a 90-day ripening period at 10°C. During ripening, biogenic amine and free amino acid content, microbiological characteristics and proximate chemical properties were observed. By the end of the ripening period, the putrescine content in both samples with the addition of the biogenic amine producing strain almost evened out and the concentration of putrescine was >800mg/kg. The amount of tyramine in the cheeses with the addition of the strain of CCDM 824 approached the limit of 400mg/kg by the end of ripening. In the cheeses with the addition of the strain of CCDM 946 it even exceeded 500mg/kg. In the control samples, the amount of biogenic amines was insignificant.