Ognjen D. Maćej

Profile and functional properties of seed proteins from six pea (Pisum sativum) genotypes.

Extractability, extractable protein compositions, technological-functional properties of pea (Pisum sativum) proteins from six genotypes grown in Serbia were investigated. Also, the relationship between these characteristics was presented. Investigated genotypes showed significant differences in storage protein content, composition and extractability. The ratio of vicilin:legumin concentrations, as well as the ratio of vicilin + convicilin: Legumin concentrations were positively correlated with extractability. Our data suggest that the higher level of vicilin and/or a lower level of legumin have a positive influence on protein extractability. The emulsion activity index (EAI) was strongly and positively correlated with the solubility, while no significant correlation was found between emulsion stability (ESI) and solubility, nor between foaming properties and solubility. No association was evident between ESI and EAI. A moderate positive correlation between emulsion stability and foam capacity was observed. Proteins from the investigated genotypes expressed significantly different emulsifying properties and foam capacity at different pH values, whereas low foam stability was detected. It appears that genotype has considerable influence on content, composition and technological-functional properties of pea bean proteins. This fact can be very useful for food scientists in efforts to improve the quality of peas and pea protein products.

Functional Properties of Pea (Pisum sativum, L.) Protein Isolates Modified with Chymosin

In this paper, the effects of limited hydrolysis on functional properties, as well as on protein composition of laboratory-prepared pea protein isolates, were investigated. Pea protein isolates were hydrolyzed for either 15, 30 and 60 min with recombined chymosin (Maxiren). The effect of enzymatic action on solubility, emulsifying and foaming properties at different pH values (3.0; 5.0; 7.0 and 8.0) was monitored. Chymosin can be a very useful agent for improvement of functional properties of isolates. Action of this enzyme caused a low degree of hydrolysis (3.9–4.7%), but improved significantly functional properties of pea protein isolates (PPI), especially at lower pH values (3.0–5.0). At these pH values all hydrolysates had better solubility, emulsifying activity and foaming stability, while longer-treated samples (60 min) formed more stable emulsions at higher pH values (7.0, 8.0) than initial isolates. Also, regardless of pH value, all hydrolysates showed improved foaming ability. A moderate positive correlation between solubility and emulsifying activity index (EAI) (0.74) and negative correlation between solubility and foam stability (−0.60) as well as between foam stability (FS) and EAI (−0.77) were observed. Detected enhancement in functional properties was a result of partial hydrolysis of insoluble protein complexes.

Fresh cheese production on the basis of milk-protein coaggregates

Two variants of fresh cheese were prepared: cheese prepared from milk heated at 650C for 30 minutes (control samples) and those prepared from milk heated for 10 minutes at 850C (experimental samples). Second method caused the protein co aggregates formation. Results of these investigations suggested that the whey obtained during fresh cheese production from co aggregates had considerable lower total nitrogen content (0.0601%) and milk fat content (0.08%). These values represented 46.37% and 33.33% of the control samples respectively. Also, dry matter of experimental whey samples was lower for 3.72% than in the whey of control samples. The cheese prepared on the basis of co aggregates had for 5.11% lower total solids content than control samples. The average values of these and control samples were 28.38% and 33.49% respectively. This may be due to protein co aggregates properties and the different structure of cheese curd. Disregarding to the higher utilization of the milk fat, the lower milk fat content in total solids content of experimental cheese is the result of higher participation of total nitrogen.

Autohthonous milk products basis for specific, original milk products development in modern conditions

A short review of characteristic processing and protection of autohthonous milk products on mountain systems, with aim to observe the importance of this processing in further development of these areas, was given in this paper. Autohthonous milk processing is a part of production which can highly effect and contribute to the animal science development and resuscitating of the area. This is a part of dairy production which was not regarded enough nor it was influenced on further processing development. Milk processing in autohthonous products is still retained at our mountain areas. Categorization of the most important product groups-cheeses, kajmak and low-fat cheeses was performed in this short review. Their basic technology characteristics, composition, properties and market value are presented. Significant relevance of original products and area, through geographic and origin protection process was emphasized. Autohthonous milk products are base for expansion of assortment and quality of original cheeses and kajmak at the market.

Characteristics of autochthonous production of Sjenica cheese at Sjenica-Pester plateau region

Characteristics and specific autochthonous technology production process of Sjenica cheese at Sjenica-Pester plateau region are presented in this paper. Sitting of Sjenica cheese autochthonous technology was performed by 22 questions opinion poll which unites basic elements and technological operations of autochthonous production. Following locations were selected Krstac, Cetanovice, Rasno, Stavalj, Karajukica Bunari, Crnis, Breza, Boljare i Leskova. Sjenica cheese had high content of moisture (53.36%). According to fat in total solids (58.42%) it belongs to a group of cheeses made of whole milk, and according to moisture on a fat-free basis (73.32%) it belongs to soft cheeses group. Sensory characteristics of cheese were good. Flavor, aroma and color had all characteristics of cheese made of ewes milk. High level of acidity and low pH value were characteristic for a group of white cheeses in brine, to which Sjenica cheese belongs.