Food and Feed Research

VALORISATION OF SHELL OF INVASIVE CRAYFISH FROM DANUBE RIVER (FAXONIUS LIMOSUS): PROTEIN EXTRACTION AND CHARACTERIZATION

Nevena Hromiš — 2024-10-23

In order to deal with invasive crayfish Faxonius Limosus impact on the native crayfish, as well as fish biodiversity in the Danube River, possible solution would be to find and adopt mechanisms for its utilizing for novel valuable products production. Apart from utilizing edible part for novel food products, shell can be also considered as a source of valuable compounds. Complex structure of shell is mainly composed of three basic compounds: chitin, protein and minerals-mainly calcium carbonate.

In this paper, shell proteins were extracted using three extraction methods. The first method was to use naturally present enzymes (proteases and lipases) in crayfish wastes and recover proteins using autolysis process. To accelerate the process, UV radiation was used. Remaining two extraction methods were alkaline extraction of proteins, where in one method alkaline extraction was applied directly to the shell and in the other method alkaline extraction followed the step of acidic demineralization of the shell. Obtained protein concentrates were analyzed for yield, crude protein content, DPPH radical scavenging ability, amino acidic content and structure.

Results have shown that similar percent of protein content was obtained by all three methods: 67-68%, but extraction yield was considerably different. Alkaline deproteinization with or without the step of demineralization resulted in 10 % yield, while UV radiation accelerated autolysis resulted in only 3,41 % yield. Although proteins extraction without using exogenous enzymes or chemicals is very interesting approach, drawback of this approach is low process yield. FTIR spectroscopy revealed secondary structure that was similar in all three concentrates, according to the peak deconvolution, whit autolitic concentrate differing in a lesser extent, having slightly higher share of b sheet structures. DPPH assay revealed high antioxidant activity of the concentrates (72-88 %), probably originating from active peptides derived from proteins and residues of carotenoides led by astaxanthin.

NUTRITIONAL STRATEGIES FOR LAYING HENS TO ADDRESS ENVIRONMENTAL CHALLENGES BY REDUCING THE NITROGEN EXCRETION

Petru Alexandru Vlaicu — 2024-10-23

This research aimed to assess the impact of incorporating Castanea sativa powder into laying hens diets, examining reduced crude protein levels and their effects on production performance, health status, nutrients and mineral digestibility and environmental pollution by nitrogen (N) excretion and absorption. For that, a 6-week trial was developed, with 90 Lohmann Brown laying hens aged 51 weeks, raised in digestibility cages, divided into three groups with 30 hens each. The diets were composed as follows: a control group fed with 17.50% crude protein (CON), an experimental group with a reduced protein level of 15.50% (RPL), and a similar reduced protein group supplemented with 0.5% Castanea sativa powder (RPCs) as tannin supplement. The limiting amino acids (lysine, methionine, and threonine) were supplemented to maintain constant equal amino acid concentrations in all experimental diets. Throughout the trial, the laying intensity was higher in the RPCs group (94.12%), followed by RLP (93.65%) and CON (91.11%). However, the CON hens yielded heavier eggs compared to RPL and RPCs groups. Average daily feed intake and feed conversion ratio showed no significant differences among the groups. Health assessments from blood samples taken at the end of the trial showed a significant effect in monocytes, and uric acid among the groups with tendencies for leucocytes, lymphocytes, heterophiles. Notably, excreted nitrogen levels were significantly reduced (up to 30%) in experimental groups compared with the CON group, showing a promising way of reducing N pollution. On the other hand, the apparent absorption of protein was higher in the groups with lower levels of protein in the diet (RPL and RPCs) compared with CON group.

Faba Bean Flour and Protein Isolate as Partial Substitutes in Wheat-Triticale Bread: A Technological and Sensory Properties

Nikola Maravić — 2024-10-24

The incorporation of faba bean flour (FBF) and protein isolate (FBI) into wheat-triticale flour blends is a potential promising strategy to enhance the nutritional and functional properties of bread. This study aimed to investigate the potential of these ingredients from both technological and sensory perspectives. Multiple analyses were conducted, including chemical composition, texture profile analysis, color, specific volume and sensory properties of breads made with a blend of wheat and triticale flours (70:30). Part of the blend was substituted with either 20% faba bean flour or 7.2% faba bean protein isolate to ensure an equal proportion of faba bean protein in the final formulations.

The results showed a significant increase in protein content for both FBF and FBPI breads, with the faba bean protein isolate also increasing the ash content. Texture profile analysis (TPA) indicated that the substitutions affected bread properties by increasing hardness, gumminess, and chewiness, particularly in bread with FBI. However, cohesiveness, springiness, and resilience decreased similarly in both cases. Additionally, the specific volume decreased with the addition of faba bean flour and protein, especially in FBI bread. From the colour aspect, analysis revealed a darker hue and a more pronounced reddish nuance in the bread crust in FBF and FBI breads. Sensory evaluation indicated a slightly lower overall likeability with faba bean addition, yet the breads remained acceptable to the panellists. Detailed sensory analysis supported the TPA findings and colour differentiation, showing higher values for hardness, crust compactness, and crumbliness. Texture and color were rated lower compared to the control sample. Moreover, both FBF and FBI breads exhibited higher overall odour intensity. Specifically, bread with the protein isolate had less uniform pores and a more pronounced flour/cereal/bran odour. In contrast, bread with faba bean flour had more uniform pores but a noticeable bitterness.

In conclusion, this study demonstrates that faba bean flour and protein isolate can be used as partial substitutes in wheat-triticale flour blends to produce bread with acceptable properties. This leaves room for future in-depth analysis and modifications to address the identified challenges.

ANTIMICROBIAL EFFECTS OF POLYPHENOLS FROM FERMENTED AND NON-FERMENTED APPLE AND CARROT POMACE AGAINST ESCHERICHIA COLI

Andrei Anghel — 2024-11-22

The pig farming industry faces significant challenges during the weaning period, often resulting in reduced growth rates and higher mortality among piglets. Traditionally, antibiotics and zinc oxide have been used to manage these issues. However, concerns about antibiotic resistance and environmental pollution have led to strict European regulations limiting or banning their use. This fact has created an urgent need for alternative solutions, with polyphenols emerging as promising candidates due to their bioactive properties, including anti-inflammatory, antioxidant, and antimicrobial effects. These properties are particularly important for preventing weaning-related problems, which are frequently caused by the Escherichia coli F4 (K88) bacterium. The present study focused on evaluating the antimicrobial properties of polyphenols extracted from apple pomace and carrot pomace, both in their unfermented form and after fermentation with Saccharomyces cerevisiae. The antimicrobial activity was assessed in vitro by monitoring bacterial growth through absorbance measurements at different intervals over 24 hours, at 37°C. The results indicated that polyphenols possess significant antimicrobial effects in both their unfermented and fermented states. The polyphenol extract from apple pomace inhibited E. coli growth at a minimum concentration of 5.6 µg (GAE)/ml, while the extract from fermented apple pomace had a higher minimum inhibitory concentration of 50 µg (GAE)/ml. For carrot pomace, only the concentration of 151 µg (GAE)/ml showed an inhibitory effect on E. coli growth, whereas the polyphenol extract from fermented carrot pomace significantly reduced bacterial growth at a concentration of 303 µg (GAE)/ml. The extent of bacterial inhibition was influenced by the concentration of polyphenols and the specific types of polyphenols present in the extract. Notably, despite having a lower overall concentration, the fermented polyphenol extracts achieved similar levels of bacterial growth inhibition as the unfermented extracts at higher concentrations. These findings highlight the potential of agro-industrial by-products such as apple and carrot pomace to provide bioactive compounds that could serve as effective alternatives to antibiotics and zinc oxide in livestock farming. By exploiting these natural resources, the industry might move towards more sustainable and environmentally friendly practices while still effectively managing the challenges associated with weaning piglets.

IMPACT OF WHEY BIOACTIVE HYDROLYSATES ON THE QUALITY OF FAT FILLINGS FOR CONFECTIONERY PRODUCTS

Milica Stožinić — 2024-11-07

Whey protein hydrolysates can be used in a wide range of applications because they offer numerous advantages compared to non-hydrolyzed whey proteins. They are more heat stable, with improved foaming and emulsifying properties due to the presence of bioactive peptides of lower viscosity. Whey hydrolysates have improved absorption, digestibility, excellent nutritional and functional properties, and the ability to extend the shelf life of food products. Due to the large differences in the technological and other physicochemical properties of hydrolysates, the addition of whey protein hydrolysates into confectionery products is much more complicated. This research aims to determine the possibilities of enriching filled confectionery products with whey peptides obtained in two ways: through enzymatic hydrolysis of whey protein concentrate and fermentation (using microorganism Lb. rhamnosus ATCC 7469). Peptides were added to a fatty milk cream at a 5% concentration. The study was focused on assessing antioxidant activity, physical, rheological, textural, and sensory properties of three fat fillings: C (control without whey peptides), EWP (5% peptides from enzymatic hydrolysis), and MWP (5% peptides from whey fermentation).Enzymatic hydrolysates increased DPPH radical inhibition by 32%, and fermented hydrolysates by 19%. Enzymatic hydrolysates also demonstrated superior inhibition of lipid peroxidation (IC₅₀value of 811.54 mg mL^-1) compared to fermented hydrolysates (IC₅₀ value of 178.36 mg mL^-1). EWP showed the highest antioxidant activity. Addition of enzymatic hydrolysates increased filling firmness by 2.5 times, while fermented hydrolysates had reduced firmness compared to the control. Both types of hydrolysates did not adversely affect the size or distribution of the particles in the fat cream. Thixotropic properties of the fat filling remained unchanged post-incorporation. MWP exhibited the most optimal rheological characteristics with the lowest yield stress. The best sensory characteristics (better than control sample) were found in the EWP.

CHANGES IN BIOACTIVE COMPOUNDS STABILITY AND COLOUR OF FUNCTIONAL PLUM SPREAD DURING DIFFERENT STORAGE CONDITIONS

Aleksandra Bajić — 2024-11-22

There is growing interest in utilizing juice pomace, including plum pomace, in new food products as a sustainable strategy for reducing waste and providing an alternative source of dietary fibers and phenolic bioactives in the functional food. Some phenolics, such as anthocyanins are more sensitive and susceptible to degradation processes in fruit preparation during storage.

This study aimed to assess the effect of a storage period and temperature on the retention of phenolics, anthocyanins (total and monomeric) and colour of functional plum spread enriched with plum pomace. The spreads were stored at 4 °C (14 days) and at 20 or 40 °C for 14, 28 and 45 days. Control sample, was also subjected to analysis one day after production and obtained measurements for investigated spreads were compared. Results revealed that total phenolics remained more stable than total anthocyanins and total monomeric anthocyanins at room temperature, while a temperature of 40 °C led to the loss of all bioactives. Colour deterioration was observed in all samples, with the least change at 4 °C. Refrigeration of sperad was found to significantly slow down the loss of phenolics and anthocyanins and better preserve colour.

EFFECTS OF NATURAL COLORANTS AND PULSED ELECTRIC FIELD TECHNOLOGY ON QUALITY PARAMETERS OF NITRITE-FREE BACON

Jan Roland Molina — 2024-12-05

The replacement of nitrites in cured meat products, such as bacon chops, presents challenges in maintaining the characteristic pink colour and other quality attributes. This study evaluates the effectiveness of natural colorants: betanin, red yeast (Monascus) rice extract, and roselle (Hibiscus sabdariffa) extract, as alternatives to nitrites for colour enhancement in nitrite-free bacon. Pulsed electric field (PEF) pre-treatment was applied to samples prior to immersing in brine with colorant. Bacon loins were treated with brines containing different concentrations of these colorants, then vacuum packaged, tumbled, and stored at 4°C until further testing. Instrumental colour parameters (L*, a*, b*, hue angle, chroma, and cured colour ratio) were measured for both uncooked and cooked samples. Results showed that uncooked bacon treated with 0.05% betanin exhibited similar redness (a*) and cured colour ratios to nitrite-treated controls, indicating that betanin has potential as a feasible colorant. Red yeast rice extract at 0.10% also enhanced redness but increased yellowness (b*), affecting the overall colour. Upon cooking, a* values of colorant-treated bacon were comparable with the nitrite-treated sample. However, they all displayed significantly (P<0.05) higher b*, hue angle, and chroma values, and decreased L* and cured colour ratio values. While PEF treatment applied did not affect the instrumental colour of the uncooked and cooked samples, it was beneficial for reducing lipid oxidation on uncooked bacon with betanin and roselle extracts. These findings suggest that while natural colorants can mimic the colour effects of nitrites in uncooked bacon, additional strategies are required to improve colour stability.

SUBCRITICAL WATER EXTRACTION OF DANDELION (TARAXACUM OFFICINALE) FLOWERS: INFLUENCE OF TEMPERATURE ON POLYPHENOLS CONTENT AND ANTIOXIDANT ACTIVITY

Tanja Brezo-Borjan — 2024-12-09

Abstract: Dandelion (Taraxacum officinale L.) has a long history in traditional herbalism worldwide. Described as non-toxic, the herb has been consumed in various forms as a valuable source of nutrients, minerals and vitamins, the consumption of which may help prevent or reduce the risk of complex diseases such as cancer, obesity, arthritis, hepatitis, cardiovascular and gastrointestinal disorders.

All parts of the dandelion herb are edible and contain flavonoids, phenolic acids, alkaloids and terpenes, with the best-studied extracts being from leaves and roots. The most abundant phenolic acids are hydroxycinnamic acid derivatives, especially chicoric acid, chlorogenic acid and caffeic acid. Luteolin and its glucosides are more abundant in extracts from dandelion leaves and flowers.

This study aimed to investigate the influence of temperature of subcritical water extraction of dandelion flowers in the interval of 110-160° C. The parameters analysed were total phenolic content (TPC), total flavonoid content (TFC), total antioxidant capacity (TAC) and the DPPH radical scavenging activity, determined by UV-spectrophotometry. The highest TPC (36.37 mg GAE/g DW) and TAC (76.80 mg AAE/g DW) were noted in extracts obtained at 140° C, while the highest TFC of 10.95 mg RE/g DW was observed when extraction was performed at 130° C. As for DPPH scavenging activity, the highest value was for the extraction temperature of 110° C (0.906 mg AAE/g DW), and the lowest for the extract obtained at 160° C (0.718 mg AAE/g DW).

The results of this study suggest that dandelion flower extracts obtained at moderate temperatures (130-140° C) with subcritical water have the highest polyphenol content and antioxidant activity.

COMPARISON OF DARK AND MILK COCOA TOPPINGS PRODUCED BY A FIVE-ROLL MILL AND A BALL MILL

Milica Stožinić — 2024-12-04

Chocolate toppings are confectionery products comprised of non-fat dark cocoa solids and sugar particles dispersed in cocoa butter, as a continual matrix. On the other hand, dark cocoa toppings contain cocoa powder and sugar dispersed in vegetable fat that is cheaper than cocoa butter, but with adequate characteristics. Also, with the addition of a 7% non-fat milk fraction, this product is regarded as a milk cocoa topping. This kind of product, dark and milk cocoa toppings, does not demand long-term conching or tempering. This study aimed to determine and compare the impact of the production process on rheology, particle size distribution and content of moisture, fats, sucrose and lactose. Based on the rheology properties, it was found that the values of the Casson and linear viscosity of the samples produced using a five-roll mill and conching were lower compared to those produced using a ball mill. Regarding particle size distribution, the results showed that the volume-weighted mean parameter D (4,3) was lower for the milk and dark cocoa confectionery topping produced in the ball mill. Additionally, the values of the yield stress in samples produced in the ball mill were 2-fold higher for the milk cocoa topping and 4.5-fold higher for the dark cocoa topping compared with the values of the samples produced using the five-roll mill and conching. The near-infrared spectroscopy (NIRS) analysis did not show any significant difference among the samples. It can be concluded that the difference between the samples produced in the ball mill and the five-roll mill and conching exists and that the ball mill can be used for the production of high-quality cocoa toppings thus providing a shorter time of production.

SNACK PRODUCTS FROM WHOLE-GRAIN RED SORGHUM FLOUR WITH PAPRIKA AND COCOA POWDERS

Elizabet Janić Hajnal — 2024-12-12

Among the cereals, sorghum (Sorghum bicolor L. Moench) is a member of the gluten-free cereal family. This crop is widely cultivated in a wide range of geographic locations due to its strong heat and drought resistance and high photosynthetic efficiency. Rich in macronutrients (proteins, fats, and carbohydrates) and micronutrients (minerals, vitamins), sorghum also contains phenolic compounds (tannins, phenolic acids, and flavonoids), which have antioxidant properties. Given its many health benefits, including its ability to suppress the formation of cancer cells and reduce obesity, heart disease, and diabetes, sorghum is used for both human and animal consumption. It can be used for baking, extrusion, and different cereal-based products such as bread, cookies, pasta, expanded snacks, and breakfast cereals. This study aimed to develop four types of snack products based on red sorghum flour (95, 92, 90, and 89%) with the addition of i) a mixture of sweet and hot ground red pepper (5, 8 and 10%); ii) cocoa powder (5, 8 and 10%); and iii) a mixture of cocoa powder (10%) and cinnamon (1%), while a 100% red sorghum snack product served as a control sample. The following extrusion processing parameters were used: feeding rate of 50 kg/h, screw speed of 800, 850, and 900 RPM, and the material moisture content in the extruder barrel ranged from 13 to 14%. The following quality attributes of snacks obtained were determined: expansion ratio, bulk density, water absorption index, water solubility index, colour and texture (hardness, number of fractures, crispiness work, crispiness index). Based on the selected quality indicators, all types of snack products obtained in this study have the potential for commercialization. However, before commercialization, consumer acceptance tests and preference tests need to be conducted.

INVESTIGATION OF THE ANTIOXIDANT PROPERTIES OF SPENT COFFEE GROUNDS EXTRACTS

Anita Milić — 2024-12-13

Coffee is one of the most consumed beverages worldwide. During coffee processing, a significant amount of by-products is generated, with coffee grounds being the primary by-product resulting from both beverage preparation and instant coffee production. The yield of bioactive compounds extracted from coffee grounds depends on the type of coffee, growing and processing conditions. The antioxidant activity of coffee grounds is mainly attributed to their high phenolic content.

The main goal of this study was to investigate the antioxidant activity of dried coffee grounds remaining in the machine after espresso preparation, with a focus on determining the total phenolic content, flavonoids and antioxidant activity through FRAP, DPPH and ABTS tests. Four solvents were used for the extraction and isolation of antioxidant components: 70% ethanol, distilled water and mixtures of 70% ethanol:water in different ratios (70% water and 30% ethanol, and 30% water and 70% ethanol).

Based on the research results, it was concluded that the solvents of ethanol and its mixtures with water presents better solution for maximizing the contents of phenols and flavonoids, as well as for achieving the highest antioxidant activity in spent coffee grounds extracts. The results of this research also suggest that coffee waste could be used as a significant source of bioactive compounds, provided that appropriate extraction solvents are used.

ANTIOXIDATIVE AND FUNCTIONAL PROPERTIES OF PLUM OIL CAKE PROTEIN ISOLATE PREPARED BY DIFFERENT DRYING METHODS

Jovana Pantić — 2024-12-13

The global demand for proteins is constantly increasing, so that science and industry have to explore novel raw materials for protein extraction. Plum oil cake, which is obtained after plum oil cold pressing, has great potential in terms of low-cost material and nutritional composition. The high protein content (up to 50%) of this by-product is ideal for valuable protein-rich ingredients extraction. Protein isolates from plum oil cake (PPI) were prepared using different drying methods- thermal drying (PPIT) and freeze-drying (PPIF). Obtained isolates were compared in terms of their antioxidative properties and functionality. Protein content and process yield were also examined, resulted in high protein content (over 96%), with no influence of drying method. Light color of PPIF would be more appealing for consumers and more suitable for incorporation in food systems. Functional properties were not significantly affected my different drying methods, except for protein solubility. Both PIs exhibited minimum protein solubility at pH 5.0 and maximum solubility at pH 10.0, while PPIF was much more soluble compared to PPIT. The freeze-drying method led to a much higher antioxidant activity of PPIF. Overall, protein isolates from plum cake obtained from different processing methods differed in appearance, solubility and antioxidant capacity, but yield, protein content and other functional properties were similar. This information will be useful to optimise the production of this protein isolate and benefit its applications.