Use of ultrasound for characterising the gelation process in heat induced tofu curd

Evaluation of physicochemical, textural, and microbial characteristics of probiotic soy cheese during storage: Generation and isolation of bioactive peptides

The purpose of this study was to ascertain how probiotic culture affected the physicochemical, textural, and microbiological characteristics of probiotic soy cheese during storage. Moreover, the release of bioactive peptides during fermentation and storage was examined. Each cheese sample was made from one of the probiotic cultures of Lactobacillus acidophilus, Lacticaseibacillus casei, and Bifidobacterium lactis. Peptide extracts were prepared from these samples and fractionated using reversed-phase high-performance liquid chromatography. The sample containing L. acidophilus had the highest dry matter and hardness. The samples with L. acidophilus and B. lactis, respectively, had the highest concentrations of lactic acid and acetic acid. During storage the acidity, dry matter, lactic acid, acetic acid, and hardness of the samples increased but the pH, springiness, and cohesiveness reduced (P < 0.05). All samples had a probiotic count greater than 107 CFU/g at the end of the storage. Antibacterial and antioxidant properties were found in the peptide fractions that were extracted from the samples. T2F4 (the fourth fraction separated from L. casei sample) had the greatest functional properties. Sodium dodecyl sulphate-polyacrylamide gel electrophoresis revealed the existence of peptide with a molecular mass of 5-10 kDa. Therefore, produced cheese is regarded as a suitable source of potentially bioactive peptides which can be utilized in food industry.

Application of ultrasound for quality control of Torta del Casar cheese ripening

This work aimed to establish the ultrasound parameters that can be useful to classify the defects in the soft cheese Torta del Casar during ripening. During ripening by ultrasound, 1 standard and 3 defective cheese batches (anomalous microbial population, inadequate pressing curd, and excessive pressing curd) were evaluated. Ultrasound parameters related to velocity, attenuation, and frequency were calculated and correlated with the physicochemical and rheological properties of the cheeses. Ultrasound data were considered variables in linear discriminant analysis to attempt cheese classification at different periods of the ripening process. Defective soft cheeses could be discriminated from standard ones with good accuracy, mainly at the final stages of ripening. The differentiation of cheese samples from 2 of the defective cheese batches (anomalous microbial population and inadequate pressing curd) from the standard was mainly attributed to different values of the attenuation-related parameters, whereas for samples from the other defective batch (excessive pressing curd), some parameters related to velocity and frequency were responsible for such discrimination.

Emerging technologies in food processing

High hydrostatic pressure (HHP), pulsed electric fields (PEFs), ultrasound (US), and cold plasma (CP) are emerging technologies that have already found application in the food industry or related sectors. This review aims to describe the basic principles of these nonthermal technologies as well as the state of the art concerning their impact on biological cells, enzymes, and food constituents. Current and potential applications will be discussed, focusing on process-structure-function relationships, as well as recent advances in the process development.

Rheological Innovations for Characterizing Food Material Properties

Rheological methods are continually evolving to encompass novel technologies and measurement methods. This review highlights novel techniques used to analyze the rheological properties of foods over the previous decade. Techniques reviewed include large amplitude oscillatory shear (LAOS) testing and rheological techniques coupled with other measurement methods, such as microscopy and nuclear magnetic resonance (NMR). Novel techniques are briefly overviewed and discussed in terms of advantages and disadvantages, previous use, and suggested future utilization.