Volume 26 (2022): Edizione 2 (December 2022)

Seven date seeds cultivars, Deglet Nour, Degla Baïdha, Fakht, Ghars, Hamraya, Tafezouin and Takermost were provided from Algerian Sahara. Some of these Algerian date seeds were studied for the first time (Fakht, Hamraya and Takermost). The biochemical characterization of these date seeds were studied, including fatty acids and minerals profiles. The results showed that date seeds are a good source of carbohydrates and crude cellulose, with averages of 66.63 and 13.20%, respectively. They are also a good source of proteins, with the cultivar Deglet Nour seeds as the richest one (9.27 ± 0.03%). The main fatty acid for all date seeds oils is oleic acid except for Deglet Nour in which lauric acid is the main one. However, the studied date seed oils could be classified as oleic-lauric oil. Potassium was the highest mineral in all date seeds cultivars, with values ranging from 2700 to 2900 mg/Kg, followed by sodium and iron. These results indicate that date seeds have good nutritional value with different compositions among cultivars. It could be concluded that date seeds could be considered as a good opportunity for their technological and industrial valorization.

The quality of the longissimus lumborum muscle has been compared in male moose, red deer, fallow der and roe deer from wild populations. The results of this study indicated that Cervid meat had favorable chemical composition and high sensory quality but its properties were affected by the species of the animal. The highest quality was characterized roe deer meat. It was found that her meat had the best water-holding capacity and was most tender, and intramuscular fat had highest nutritional value. However, due to the high diversity and variation of factors affecting game meat quality, further research is needed to confirm the observed interspecific differences between members of the family Cervidae.

The aim of the study was to modify and adapt to other matrices the fast and simple method for determining total lipid content expressed as fatty acid methyl esters (FAME) by performing the in situ transesterification. The primary method was published as a technical report for the FAME analysis in algae dry mass. Our modifications included the use of less toxic solvents, the use of an internal triglyceride standard and FAME determination by the gas chromatography technique coupled with the mass spectrometry technique in the Single Ion Monitoring mode (SIM). The modified method was validated for 37 fatty acids (saturated, monounsaturated and polyunsaturated) containing from four to twenty-four carbons in the carbon chain (C4-C24), and was adapted to five food matrices: three solids (yeast, yeast flakes, biscuits), and two liquids (milk thistle (Silybum marianum (L.) Gaertner) oil and olive oil). Additionally, 14 samples of spices and superfood samples, rich in unsaturated oils were analyzed. The validation parameters: linearity, precision, recovery, limits of detections and quantifications, were assessed and additionally Certified Reference Material of olive oil was analyzed.

During storage, sea-buckthorn berries which are a valuable source of bioactive compounds, gradually lose their optimum mechanical properties and chemical characteristics. Mechanical and chemical properties of sea-buckthorn berries were examined in fruit exposed to gaseous ozone at a rate of 10 and 50 ppm for 15 minutes. Ozonation process did not impact mechanical properties (except for elastic modulus) or morphological characteristics, but it resulted in decreased water loss, on average by 5.21%, in fruit kept in cold storage for 14 days, as well as increased pH and reduced acidity of sea-buckthorn berries on average by 9.03% and 20.0% (for ozone concentration of 50 ppm) compared to the control sample. Polyphenol contents in sea-buckthorn berries were identified using UPLC-PDA-MS/MS. Out of all the identified polyphenols, the findings showed the highest contents of flavone glycosides, represented e.g., by isorhamnetin-3-O-rutinoside. The contents of bioactive compounds (ascorbic acid, total polyphenols or polyphenol profile) as well as antioxidant activity (measured using DPPH^. and ABTS^+. assays) were different, depending on the variety and possibly were affected by the timing of sea-buckthorn fruit harvest.

Migratory locust has been widely reported as a quality protein source. However, there are food safety problems related with the usage of insects as food. In this study, migratory locust powder (MLP) was used as a protein supply alternative to milk powder (MP) in peanut-based RUTFs. Seven formulations were obtained at different substitution levels (0 – 30%) of MP with MLP. Pesticide residues, aflatoxins, triazine and toxic metals were analysed using a GC-MS system and Atomic Absorption Spectrophotometer. Formulation with 30% MLP and without milk have the highest level of organochlorine (3.22 µg/kg), organophosphorus (0.40-4.56µg/kg) amongst others. Aflatoxins of the therapeutic foods increased with increasing levels of MLP. The heavy metals, melamine, and cyanuric acid of the RUTFs were below the standard permissible limits. Migratory locust powder could be used as an alternate protein source in the formulation of peanut based RUTFs without posing health threat.

Milk products are widely consumed as a beverage and used as the main ingredient in many food applications. Beetroot is suitable as an ingredient for the natural red color in food products. Color stability of natural colorants is mainly affected by mixtures of materials and temperatures. The effect of beetroot juice concentration and types of carrier agents on the physical properties of the red-colored skim-milk powder and rehydrated powder at different temperatures were studied. Beet juice concentration significantly affects the redness (a*) and lightness (L*) of skim milk in both powders and reconstituted forms. Powder with mixtures of maltodextrin and Arabic gum showed better retention of redness, high solubility, low moisture content, water activity, and less hygroscopic. The finding from this study may benefit food product development, beverage, and confectionery in the food industry.

The purpose of this study was to evaluate the effect of wheat-mesquite composite flour on the rheology of dough and the quality of bread. The farinographic analysis showed a decrease in the development time and stability of the dough with an increase in the mixing tolerance index. The share of mesquite flour increased the value of loss and storage moduli and reduced the dough’s susceptibility to stress. The mesquite flour addition increased the bread volume by about 17% and the number of large pores >5 mm. The brightness of the crumb containing mesquite flour decreased from 75.3 to 58.6 and the proportion of yellow colour increased from 19.9 to 26.4 in relation to the control bread. The bread with mesquite flour had a significantly softer crumb during storage in comparison with wheat bread, indicating a reduction in the staling. These observations were also confirmed by lowering the disintegration enthalpy of the retrograded amylopectin from 3.33 J/g for the control sample to 1.95 J/g for the bread containing 10% of mesquite flour.

Cassava root flours from five different cultivars (C-MSAF2, C-P4/10, C-P98/0505, C-P98/0002, and C-UKF8) were studied for their potential application in the food industry. Proximate composition, functional, thermal, and pasting properties were investigated. Cassava flours were high in carbohydrates (85-86%) and their amino acid profiles varied. Cultivars C-MSAF2, C-P98/0002, and C-UKF8 showed high protein content (5.06%), mineral content (2.36%), and the largest particle size (72.33 µm), respectively. Solubility of cassava flours decreased as temperatures increased, however, swelling power and water absorption capacity increased. C-MSAF2 showed the highest peak viscosity, breakdown viscosity, and shortest peak time. C-P98/0505 showed the highest final viscosity, the highest pasting temperature, and the longest peak time. Cassava flours studied are promising candidates for utilization in the baking industry, however, their incorporation into baked product formulations needs further investigation.

The purpose of this study was to determine the effect of simplified tillage systems (RT, NT) in comparison with conventional tillage (CT) on technological grain quality and baking value, as well as of hybrid wheat grown under variable weather conditions. A three-year field trial experiment was conducted using a randomised block design, in triplicate. The factors studied were as follows: I - three tillage systems - no-tillage (NT), reduced (RT), and conventional (CT); II - two winter wheat cultivars ‘Hylux’ (cv. hybrid) and for comparison ‘Bogatka’ (cv. common). The use of CT and RT tillage systems compared to NT significantly increased yield by 8.9 and 7.7%, respectively, and selected grain quality parameters along with a more favorable gluten protein profile. The flour obtained, with water absorption above 58.0%, can be classified as strong flour with good farinographic and alveograph parameters. The genetic characteristics of the wheat cultivars determined the technological quality of the grain and the baking value, as well as the grain yield. For ‘Hylux’ cv. hybrid wheat, there was a higher yield and better grain quality, which contained significantly more gliadins and glutenins, and the flour was characterised by higher parameters that determine the preferred viscoelastic properties of the dough. The common ‘Bogatka’ wheat cv. accumulated higher contents of ω gliadins and LMW and HMW glutenin subunits in the grain, while for α/β and γ gliadin contents the difference was not significant. A fairly dry period (June–July) of wheat ripening reduced the grain yield but was favourable for higher values of quality characteristics, gluten protein fractions, as well as the farinographic (WAF, DDT, DS) and alveograph (W, P, L) parameters.

In most developing nations, there has been an increase in the consumption of wheat-based products, particularly biscuits, due to recent lifestyle changes and rapid urbanization. Due to this, there has been a sudden rise in research into creating flour from locally grown cereals or legumes to satisfy consumer demand. As a result, the potential for making biscuits with sorghum-soy composite flour was investigated. The flour blends and the corresponding biscuit products’ functional and physicochemical characteristics were established. The samples of biscuits’ organoleptic characteristics were also identified. The functional properties of the composite flours decreased while their proximate composition increased, according to the results. As the amount of sorghum-soy flour inclusions increased, the physical characteristics of the biscuit samples decreased. The moisture contents, protein contents, crude fats, ash, crude fibers, and carbohydrates were all within the ranges of 3.11 to 3.80%, 14.80 to 17.66%, 5.07 to 5.51%, 3.65 to 4.94%, 2.66 to 3.64%, and 66.11 to 70.71%, respectively. The sorghum-soy biscuits fared well compared to the wheat-based biscuits and were deemed acceptable. As a result, eating these biscuits will increase people’s nutrient intake, particularly that of children, as well as the utilization of sorghum and soybean in tropical nations.

Biosurfactants have wide applications in several industries. However, high production costs and safety concerns have limited their comprehensive use. Twenty-five strains of lactic acid bacteria, isolated from fermenting maize slurry, were screened for biosurfactant production using the emulsification activity (E₂₄) assay. The selected bacterium was identified molecularly using the 16S rRNA gene sequencing as Lactobacillus plantarum OG8. The effect of some cultural factors on biosurfactant production from the bacterium, using pineapple peel as a low-cost substrate, was investigated. The optimum yield of biosurfactant occurred at a 48 h incubation period, using glucose and peptone as carbon and nitrogen sources, respectively. The biosurfactant was characterized to possess mostly carbohydrates, followed by protein and lipid contents. Optima pH 10.0 and temperature 60 °C were the best for the biosurfactant activity. The biosurfactant exhibited antimicrobial activity against bacterial pathogens Staphylococcus aureus, Bacillus subtilis, Escherichia coli, and Klebsiella pneumoniae, at a concentration of 5.0 mg/mL. The use of pineapple peel as a low-cost substrate for biosurfactant production from Lactobacillus plantarum OG8 will serve for cost-effective production. The biosurfactantt produced exhibited promising properties such as thermostability and antimicrobial activity against food spoilage and pathogenes that could make it suitable for food processing and preservation.

Natural kefir grains are rich in beneficial bacteria, and analysis of their microbial diversity is a necessary condition for developing and applying kefir grains. In this study, six commercially available natural kefir grains were used as raw materials to explore their microbial diversity by metagenomics. The results showed that there were 14794 genes in 6 kinds of natural kefir grains, and the number of unique genes of X1, X2, X3, X4, X5, X6 were 111, 11, 0, 1899, 552, 1, respectively. From the relative abundance table of boundary, phylum, class, order, family, genus and species, the microbial diversity at each level was analyzed.The two dominant genera at the genus level are Lactobacillus and Lactococcus, and the dominant species at the species level are Lactococcus lactis and Lactococcus kefiranofaciens, Lactococcus crispatus, and Lactococcus helveticus, etc. Species distribution and species diversity of each sample were analyzed by species heat map, principal component analysis and non-metric multidimensional calibration methods. The results showed that the microbial diversity of natural kefir grains from 6 different sources were different. The research can provide reference for the development and application of natural kefir grains in the field of dairy products.

Exopolysaccharides (EPS) can not only give food a unique texture but also has antioxidant capacities. To select the medium composition that influences the yield and antioxidative activity of EPS, Plackett–Burman (PB) design was employed to appraise the effects of carbon sources, nitrogen sources, and inorganic salts on yield and DPPH free radical scavenging (DPPH-FRS) rate of EPS in MRS medium fermented by Lactobacillus fermentum B62. The result indicated that sucrose (p<0.01), peptone (p<0.01), and KH₂PO₄ (p<0.001) had the most distinguishing comprehensive effects on yield and DPPH-FRS rate of EPS, and fructose also had a noticeable effect on the two factors (p<0.05, p<0.001, respectively). Additionally, glucose (p<0.05), soy protein (p<0.001), yeast extract (p<0.01), KH₂PO₄ (p<0.001) and Ca(H₂PO₄)₂ (p<0.001) significantly positive affect the yield of EPS. And inulin (p<0.05), tryptone (p<0.001), beef extract powder(p<0.001), NaH₂PO₄ (p<0.01) and C₂H₃NaO₂ (p<0.05) significantly positive affect the DPPH-FRS rate of EPS. Within the test ranges, sucrose, fructose, peptone and KH₂PO₄ all showed significant positive relativity to the yield and anti-oxidative activity of EPS.