Effects of Fish Protein Hydrolysate on the Nutritional, Rheological, Sensorial, and Textural Characteristics of Bread.

The potential enhancement of the protein content in bakery products is studied by adding fish protein hydrolysate (FPH) flour in varying proportions (1.5%, 3%, 4.5%, and 6%) within the production recipe. The mixtures of wheat flour and FPH obtained were comprehensively analysed using Mixolab equipment, evaluating the nutritional, rheological, and enzymatical aspects. The results underscore the substantial potential of FPH as a high-quality protein source evidenced by its polyphenol content and antioxidant value. Moreover, the utilisation of hydrolysed proteins from fish emerges as a viable strategy for reducing the water footprint in food production. Thus, FPH flour showed a protein content of 80.21%, a polyphenol content of 1452 mg GAE/100 g, and an antioxidant activity of 294 mg TE/100 g. While the bread samples made from wheat flour mixed with FPH exhibited a satisfactory rheological behaviour, the presence of an aftertaste and the pronounced fish aroma impacted consumer acceptance. Notably, only the bread sample with 1.5% added FPH met the organoleptic preferences of the consumers, receiving a commendable total acceptability score of 6.2. Additionally, this sample demonstrated favourable results in texture analysis and exhibited an extended shelf life compared to that of the control sample.

Potential for Saccharina latissima Flour as a Functional Ingredient in the Baking Sector.

The healthy "superfood" sector is currently quickly developing in Europe, and grocery stores are increasingly stocking macroalgae food supplements. Due to its high amount of protein, fiber, and minerals, numerous studies have demonstrated that seaweed has a significant potential for usage as a functional ingredient in the food sector. The aim of the current study was to evaluate the rheological (ICC 173 standard method) and chemical potentials of using Saccharina latissima flour in the bread sector. The calcium level of S. latissima flour was found to be 8236 mg/kg, the magnesium level was 6041 mg/kg, the K concentration was 62,088 mg/kg, the iron content was 35.23 mg/kg, the P content was 2263 mg/kg, and the I content was 12,530 mg/kg, significantly higher values than those of wheat flour. The antioxidant properties of the algae powder used were highlighted by the analysis of the total polyphenol content and its antioxidant activity (DPPH method). Four bread samples, which were compared with the control sample entirely made of wheat flour in order to evaluate their potential, were made, using a replacement degree from 1.5% to 6% of S. latissima. Rheological analyses were completed using the ICC 173 standard method, as well as sensorial analysis, where a panel of assessors' evaluations compared the sensory properties of samples with 1.5-6% of S. latissima flour to a control sample manufactured with flour type 650. It was concluded that sample A1 (1.5% algae flour) has sensorial properties similar to those of the control sample, and, for the other samples, the properties began to degrade with the increase in the amount of algae flour. Textural analyses performed during 96 h of storage show that the firmness and gumminess increase with the addition of algae flour and over time. The conclusions indicated that samples comprising 4.5% and 6% of S. latissima are unsatisfactory from a rheological and sensory perspective, while samples having 1.5% and 3% of S. latissima can be viewed as sources of fiber and minerals.

Physicochemical and functional properties of rainbow trout (Oncorhynchus mykiss) hydrolysate.

Due to the continuous growth of the world population, there is an urgent need to find sustainable sources of high-quality protein. Fish side streams rich in essential nutrients and accounting for 60-70% of the whole fish, represent a sustainable source for recovery of valuable protein compounds. The present study aimed at extensive characterization of physicochemical, antioxidant and techno-functional properties of fish protein hydrolysate (FPH) obtained from farmed rainbow trout (Oncorhynchus mykiss). The FPH was produced from a minced rainbow trout raw material by enzymatic hydrolysis performed at 50 °C with addition of 0.05% w/w papain and 0.05% w/w bromelain. After inactivation of the proteases at 90 °C for 10 min, the content of the bioreactor was centrifuged, and the soluble protein fraction (FPH) was collected and freeze-dried. The total protein content of the FPH with 17.24% degree of hydrolysis was high (88.9%) and mainly represented by water-soluble proteins, while the lipid content was below 1%. In addition to the high protein content, trout hydrolysate had low protein oxidation values characterized by a relatively low total carbonyl content together with high amount of thiol groups (3.64 ± 0.31 and 20.7 ± 0.6 nmol/mg protein, respectively). No glass transition was detected in the differential scanning calorimetry (DSC) heat flow curves, suggesting lack of unfreezable solution formation in the FPH at freezing temperatures. The viscosity of FPH showed typical Newtonian behaviour. A peptidomic investigation (using HPLC-MS/MS technique) displayed chemical composition of the trout hydrolysate and identified peptide sequences which are present in the hydrolysate mixture, as well as proteins to which each peptide belongs to. In conclusion, it was suggested to use the obtained trout hydrolysate as a functional ingredient in the food and nutraceutical industry.

Evolution of proteolytic and physico-chemical characteristics of Norwegian dry-cured ham during its processing.

Proteolytic activity and physico-chemical characteristics were studied for Norwegian dry-cured ham at four different times of processing: raw hams, post-salted hams (3 months of processing), hams selected in the middle of the production (12 months of processing) and hams at the end of the processing (24 months). Cathepsin H activity decreased until negligible values after 3 months of processing, whereas cathepsins B and B+L were inactive at 12 months. AAP was the most active aminopeptidase whereas RAP and MAP were active just during the first 12 months of processing. Proteolysis index reached a value of 4.56±1.03 % with non-significant differences between 12 and 24 months of ripening. Peptide identification by LC-MS/MS was done and two peptides (GVEEPPKGHKGNKK and QAISNNKDQGSY) showing a linear response with the time of processing were found. Unfreezable water content and glass transition temperature were investigated using differential scanning calorimetry (DSC) technique with non-significant differences in the temperature of glass transition for 12 and 24 months of processing.