Microstructural properties of fat during the accelerated ripening of ultrafiltered-Feta cheese

Impact of Pressing Time on the Microstructure of Two Types of Goat Cheeses and Its Relationship With Sensory Attributes

The objective of this study was to study the impact of pressing time on the microstructure of goat cheese and its relationship with sensory attributes. The microstructure of the artisanal cheeses was performed by scanning electron microscopy and image analysis. The validation of the microstructural complexity was carried out experimentally with sensory attributes. The pressing time influenced the microstructural parameters Feretmax, Geodiam, and τ and the cheese type influenced the parameters Feretmax, Geodiam, and Geoelong. The correlation values between microstructural complexity and sensory attributes were 0.85 and 0.84 for fresh cheeses and matured cheeses, respectively. The pressure times of 12 and 18 h resulted in cheese microstructures with the highest complexity in terms of Feretmax, Geodiam, Geoelong, and τ parameters. The obtained results are supported by the correlation values between microstructural complexity and sensory attributes.

Production of Low-fat mayonnaise without preservatives: Using the ultrasonic process and investigating of microbial and physicochemical properties of the resultant product

In this study, ultrasonication was used at 20 kHz, 750 W for 5 min, as a nonthermal alternative to pasteurization and as a substitute for benzoate-sorbate preservatives. Also, its efficiency on microbial and physicochemical properties of low-fat mayonnaise stored at 4°C was investigated. The results showed the reduction of total counts of micro-organisms, acid-tolerant bacteria, molds, and yeasts during six months shelf life compared with the control samples. Sonicated mayonnaise samples had lower pH values and higher acidity in comparison with control samples during the storage. The speculation was verified through the microstructure of mayonnaise samples during storage time observed by SEM micrographs. The overall results indicated that it was possible to produce sodium benzoate and potassium sorbate-free mayonnaise using the ultrasonic nonthermal method.

Microbial lipases and their industrial applications: a comprehensive review

Lipases are very versatile enzymes, and produced the attention of the several industrial processes. Lipase can be achieved from several sources, animal, vegetable, and microbiological. The uses of microbial lipase market is estimated to be USD 425.0 Million in 2018 and it is projected to reach USD 590.2 Million by 2023, growing at a CAGR of 6.8% from 2018. Microbial lipases (EC 3.1.1.3) catalyze the hydrolysis of long chain triglycerides. The microbial origins of lipase enzymes are logically dynamic and proficient also have an extensive range of industrial uses with the manufacturing of altered molecules. The unique lipase (triacylglycerol acyl hydrolase) enzymes catalyzed the hydrolysis, esterification and alcoholysis reactions. Immobilization has made the use of microbial lipases accomplish its best performance and hence suitable for several reactions and need to enhance aroma to the immobilization processes. Immobilized enzymes depend on the immobilization technique and the carrier type. The choice of the carrier concerns usually the biocompatibility, chemical and thermal stability, and insolubility under reaction conditions, capability of easy rejuvenation and reusability, as well as cost proficiency. Bacillus spp., Achromobacter spp., Alcaligenes spp., Arthrobacter spp., Pseudomonos spp., of bacteria and Penicillium spp., Fusarium spp., Aspergillus spp., of fungi are screened large scale for lipase production. Lipases as multipurpose biological catalyst has given a favorable vision in meeting the needs for several industries such as biodiesel, foods and drinks, leather, textile, detergents, pharmaceuticals and medicals. This review represents a discussion on microbial sources of lipases, immobilization methods increased productivity at market profitability and reduce logistical liability on the environment and user.

Effect of Quinoa (<i>Chenopodium quinoa</i>) Flour on the Production and Quality of Low-Fat Camel Milk Processed Cheese Spread

BACKGROUND AND OBJECTIVE

Camel milk has nutritional and therapeutic properties. Quinoa flour has been incorporated into many kinds of food because of its various nutrients and bio-actives. This study aimed to investigate the effect of using quinoa flour on the properties of low-fat camel milk processed cheese spread (LF-CMPCS) made from fermented retentate camel milk as a camel cheese base.

MATERIALS AND METHODS

Quinoa flour was used to substitute 1, 3 and 5% of the camel cheese base made with Ras cheese. The resultant cheeses were analyzed for several parameters. Such as physiochemical, texture properties, antioxidant activity, fatty acids, microstructure and organoleptic properties as fresh and during storage period at 5±1°C for 3 months. The data were analyzed by ANOVA using the SPSS computer program.

RESULTS

Total solids, protein, fat/dry matter and soluble nitrogen decreased significantly while the fiber, carbohydrates and pH values increased significantly. Meltability value of LF-CMPCS significantly decreased. The results indicated that the hardness increased significantly with the increase in the addition of quinoa flour. The fatty acid profile indicated a significant increase in oleic acid (18:1), linoleic acid (18:2), linolenic (18:3) and eicosenoic (20:1) with the increase of quinoa flour. Scanning electron microscopy (SEM) images showed the presence of quinoa flour in the space within the casein particle network.

CONCLUSION

It could be concluded that the addition of quinoa flour to camel cheese (up to 3%) can improve the chemical, sensory and microstructure and texture properties of LF CMPCS camel milk cheese without altering the quality of the product.

Acceleration of Swiss cheese ripening by microbial lipase without affecting its quality characteristics

The effect of exogenous microbial lipase enzyme on the ripening of Swiss cheese (0, 200, and 800U lipase in 30 L milk) was investigated for the physico-chemical, textural and sensory properties, along with its microstructure. The aim of this study was to investigate the application of microbial lipase to accelerate the ripening without affecting its original desirable quality characteristics. The effect of the microbial lipase was studied at different time periods (2, 30, 45, and 60 days) of the Swiss cheese ripening stages. Statistical analysis of the results showed that the physico-chemical parameters of cheese slightly increased during the ripening. Also, at all stages of the ripening hardness of Swiss cheese increased while the brittleness decreased. The number and size of the fat globules were also affected by the addition of the lipases. This study also showed that increase in the lipase amount had no significant change in quality and sensory parameters. Therefore, 200U of lipase was found to be sufficient to reduce the ripening time from 90 to 60 days by maintaining its genuine quality. Thus, this study suggested that the addition of microbial lipase may significantly reduce the cost of the cheese production by lowering the ripening period by 1 month and maintaining the quality of the final product.

Effect of inulin on physico-chemical, sensory, fatty acid profile and microstructure of processed cheese spread

To develop a functional processed cheese spread (PCS) different levels of inulin (0, 4, 6 and 8%) addition into PCS was studied with its physico-chemical, sensory and fatty acid profile and micro-structural quality. As the level of inulin addition increased moisture, a_w and titratable acidity, decreased. At the highest level of inulin addition (8%) sensory panelists reported a significant decrease in total sensory score. PCS with 6% insulin was found to have optimum from quantity. The addition of inulin in cheese spread decreased both total saturated fatty acid and unsaturated fatty acid and in unsaturated fatty acid, mono unsaturated fatty acid decreased; however, polyunsaturated fatty acids increased as compared to the control. Scanning Electron Micrograph of PCS containing insulin showed uniform distribution of insulin with diameter ranged 4-10 µm in the protein matrix.

Effect of Persian and almond gums as fat replacers on the physicochemical, rheological, and microstructural attributes of low-fat Iranian White cheese

The effect of Persian and almond gums (0, 0.1 and 0.2% (w/w)) as fat replacers and milk fat (0.4, 0.9, and 1.4% (w/w)) on physicochemical and rheological characteristics and microstructure of low‐fat Iranian White cheese was studied. Persian and almond gums both effectively increased moisture‐to‐protein (M:P) ratio of low‐fat cheese samples which in turn led to a significant reduction in the hardness parameters fracture stress and Young's and storage (G’) moduli (p < .05); however, the effect of Persian gum was more pronounced (p < .01). Gum addition promoted cheese yield and proteolysis rate (p < .05). Response surface optimization described that supplementation of cheese milk containing 0.9% fat with 0.2% Persian gum and 0.12% almond gum would result in a low‐fat cheese with textural properties similar to its full‐fat counterpart. Scanning electron microscopy revealed that the fat replacers produced full‐fat‐like structure in the low‐fat Iranian White cheese, when incorporated at the optimum levels.

The influence of salt concentration on the chemical, ripening and sensory characteristics of Iranian white cheese manufactured by UF-Treated milk

Iranian White cheese was manufactured from ultrafiltered cows’ milk using different concentrations of salt consisting of 1, 2·5, 4% and salt free. Chemical composition, proteolysis, counts for lactic acid bacteria and sensory evaluation were examined during 90 d of ripening. It was found that the use of different salt concentrations significantly influenced all chemical composition, proteolysis, total number of lactic acid bacteria and sensory characteristics of the cheeses. Increasing the salt concentrations caused a proportional decrease in proteolysis determined by both urea-PAGE of caseins and RP-HPLC of peptides. With increased salt concentration, total number of lactic acid bacteria decreased. Cheeses with 1 and 2·5% salt were suitable and acceptable in odour and flavour that may be due to the proportional level of proteolysis products. In conclusion, reducing salt concentration from 4 to 2·5 and 1% had no ineligible effect on the quality and acceptability of the cheese.