Plastic packaging has been widely criticized due to the environmental pollution it entails. Biopolymer‐based films could provide an interesting eco‐friendly alternative. This study aimed to ...investigate the effect of plasticizer type on the physicochemical and mechanical properties of gelatin, pectin, starch, gelatin/pectin, gelatin/starch, and starch/pectin‐based films. Films were prepared using the casting method. Among the six types of films studied, gelatin/pectin‐based film plasticized with sorbitol displayed the best functional properties. Tensile strength and elongation at break were 52.46 MPa and 19.80%; moisture content, water vapor permeability, and water resistance were 19.96%, 3.24 × 107 g s–1 m–1 Pa–1, and 19.96%, respectively. Mentha pulegium and Lavandula angustifolia essential oils were incorporated into the selected film and their effects on the film's characteristics were evaluated. The incorporation of essential oils resulted in films with enhanced antibacterial properties, lower water vapor permeability, and reduced mechanical properties.
Practical applications
Biopolymer‐based films have attracted widespread attention as an alternative to plastic packaging. In this study, we have demonstrated that gelatin/pectin‐based film plasticized with sorbitol at 30% displayed good mechanical and physicochemical properties. The incorporation of Mentha pulegium and Lavandula angustifolia essential oils into this matrix resulted in films with important antimicrobial activity and adequate mechanical and physicochemical characteristics. The selected combination could be used as bioactive packaging to preserve and prolong the shelf life of food.
Biopolymer‐based films present numerous environmental advantages. The current study aims to investigate the impact of storage time on the antimicrobial, antioxidant, and functional properties of ...pectin‐based films containing Thymus capitatus (TEO) and Cinnamomum verum (CEO) essential oils (EOs). Films were prepared using the solution casting method; their different properties were evaluated over 1 month at room temperature. Both types of films displayed strong antimicrobial activity against Staphylococcus aureus (S. aureus), Listeria monocytogenes (L. monocytogenes), Escherichia coli (E. coli), and Salmonella typhimurium (S. typhimurium). Pectin‐based film incorporated with CEO displayed greater antioxidant activity than film incorporated with TEO. The two EOS increased the films' elongation at break and tensile strength. However, their moisture content and thickness decreased. The antibacterial and antioxidant activities of the CEO‐ and TEO‐based films decreased after 4 weeks of storage, while moisture content increased. However, the films' mechanical parameters remained stable during the entire storage period.
Biological and functional properties of pectin‐based film incorporated with essential oils.
Legume plants rely upon multipartite interactions between rhizobia and bacterial endophytes within root nodules to facilitate plant growth. This study aimed to isolate and identify indigenous ...endophytic bacteria from root nodules of
Sulla aculeolata
L. in Northeast Morocco. Based on their tri-calcium phosphate (TCP) solubilization capacity, five endophytes were chosen for further evaluation of their plant growth traits. All isolates were hydrogen cyanide (HCN) and siderophore producers, while only BCH24 tested positive for ACC deaminase activity. Indole-3-acetic acid (IAA) synthesis ranged from 1.27 mgL
− 1
to 2.89 mgL
− 1
, while soluble phosphate concentrations was between 7.99 mg L
− 1
and 110.58 mg L
− 1
. Additionally, all the endophytes were able to produce more than two lytic enzymes. Based on the analysis of 16 S rRNA gene sequences five isolates were identified as
Enterobacter
sp (BCH13, BCH2),
Pseudomonas
sp (BCH16, BCH24), and
Serratia
sp (BCH10). The strains inhibited the growth of three phytopathogenic fungi, with BCH13 exhibiting the highest rate against
Aspergillus ochraceus
(45%), followed by BCH24 against
Fusarium oxysporum
(40%) and
Botrytis cinerea
(35%), respectively. In vivo inoculation of halotolerant strains
Enterobacter hormaechei
(BCH13) and
Pseudomonas moraviensis
(BCH16) under gnotobiotic conditions revealed that co-inoculation with
Rhizobium sullae
KS6 improved plant development compared to single inoculation, making it a promising eco-friendly bio-inoculant for legume
Sulla flexuosa
L. production.
The hake (Merluccius merluccius) fishery occupies an important place in the Moroccan trawl fishery. Despite the ecological and commercial value of this species, the reproductive biology of European ...hake populations in Moroccan coastal waters has been little studied. Here, we describe the seasonal variations of gonad histology of hake collected from August 2017 to August 2018 along the northern Atlantic coast of Morocco. The histological changes were compared with macroscopical changes, and the body length at first maturity (L50) was calculated. The results revealed differences between macroscopic and histological maturity staging of the gonads. The L50 was estimated to be 34.7 cm for females and 28.6 cm for males (histology-based) and 30.6 cm for females and 26.8 cm for males (macroscopy-based). In addition, the observations of ovarian maturity indicated the presence of a protracted spawning season throughout the year with a peak around January and in midsummer.
The effect of gelatin-based edible coating incorporated with Mentha pulegium essential oil (MEO) on physicochemical (pH, titratable acidity (TA), weight loss, total soluble solids (TSS), and total ...phenolic content (TPC)), microbiological (total aerobic mesophilic flora (TAMF) and yeasts and moulds (YM)), and sensorial (color and firmness) characteristics of strawberries stored under refrigeration was studied. Strawberries were coated with gelatin alone (4%) and/or gelatin combined with two concentrations (0.5 and 1%) of MEO and stored at 4°C for 13 days. Gelatin coating and MEO combination significantly inhibited total flora and moulds and yeasts with comparison to control (uncoated strawberries) and had better hygienic quality at the end of storage. The effect was MEO concentration dependent. Our results also showed that the bioactive coating used in this investigation slowed down changes in pH, TA, weight loss, TSS, firmness, TPC, and color of strawberries. Gelatin coating incorporated with MEO at 1% protected at least 60% of strawberries from deterioration after 13 days of storage and could be used as bioactive packaging to prolong the shelf life and an alternative of pesticides use.
•M. merluccius showed positive allometric growth, with females grew faster than males.•The longevity of M. merluccis is up to 10 years.•The high rates of total mortality and exploitation revealed the ...overexploitation of this stock.
Growth and mortality studies on fish are considered crucial to the comprehension of species biology and population dynamics. This work aims to study the growth and mortality of Merluccius merluccius (Linnaeus, 1758) from the North Atlantic coasts of Morocco. A total of 1001 European hakes was sampled from trawler’s fishery during the period from August 2017 to August 2018. Growth parameters were computed for the European hake males and females by applying the von Bertalanffy growth formula. The asymptotic lengths (L∞), growth coefficients (k) and the theoretical age at zero-length (t0) for females and males were; L∞ = 80.19 cm, k = 0.27 year−1, t0 = –0.472 year−1, and L∞ = 69.15 cm, k = 0.31 year−1, t0 = –0.426 year−1, respectively. The total mortality rate (Z), natural (M) and fishing mortality (F) were estimated as Z = 1.49, M = 0.51 and F = 0.98 for combined sexes. The estimated exploitation ratio (E = 0.66), indicated overexploitation of the M. merluccius in the North Atlantic coasts of Morocco.
Lotus spp. are a plant of great importance as a forage to improve pastures, to restore degraded soils and the inoculation with best rhizobial strains is widely used in many countries. The aim of this ...work was to analyze the phylogeny of bacteria nodulating Lotus creticus collected from sandy alkaline saline soil in Tangier province Northern Morocco and determine their identity. Out of 44 bacterial isolates, 21 strains were selected for the phenotypic characterization and symbiotic efficiency evaluation. The enterobacterial repetitive intergenic consensus (ERIC)-polymerase chain reaction (PCR) fingerprinting showed different patterns at 40% similarity, and the amplified ribosomal DNA restriction analysis (ARDRA) generated one ribotype. Based on both the ERIC-PCR and the ARDRA results, 2 isolates, LcT51 and LcA30, were then chosen for molecular analysis. The 16S rRNA gene sequences showed that the 2 strains are closely related to Ensifer meliloti LMG 6133T with similarity values of 99.69%% to 99.93%. The analysis of concatenated atpD, glnII, gyrB, rpoB and dnaK housekeeping genes sequences confirmed the affiliation of the two strains to E. meliloti LMG 6133T. The phylogenic analysis of the nodC and nifH symbiotic genes, confirmed that L. creticus is nodulated in Tangier alkaline soils by the symbiovar lancerottense of E. meliloti.
Goat milk, a highly nutritious product is widely used in cheese making. In order to properly select suitable milk samples for production, fifty-five samples of raw goat’s milk were collected from ...eight farms in the North-West of Morocco to analyze their counts of various mesophilic bacteria and determining the physicochemical characteristics during different seasons of the year. Lactic acid bacteria (LAB) were isolated, identified, and screened for several technological properties. Overall mean values for mesophilic aerobic flora were above 7.10 log cfu/mL in spring and 5.80 log cfu/mL during winter with a statistically significant difference found between all the microorganisms except for coagulase-positive staphylococci. The physical and chemical composition tests showed higher values for fat (4.9±1.01%), dry matter (13.98±0.95%), ash (1.3±0.12%), lactose (3.1±0.65 g/L), and protein (4.6±1.03 g/L) during the winter season which could be of great interest for cheese production. fatty acids (FA) composition mainly consisted of saturated fatty acids (SFA) in both seasons. Lactococci isolates were the most acidifying (pH6h=4.35–pH24h=4.08) while Lactobacillus paracasei produced the highest proteolytic activity (66.93±2.63 mgTyr.L-1) and diacetyl-acetoin (54.83±0.46 mg diacetyl/L). None of the tested isolates were lipolytic, however, several lactobacilli and lactococci exhibited a high salt tolerance and exopolysaccharide (EPS) production. Lactobacillus plantarum exhibited the highest lysis rate (67.34±1.76%) while the antibacterial profile ranged between 10.5±0.137 and 22.9±0.23 mm. The obtained results highlight the importance of Moroccan goat milk as a valuable component for cheese making due to its rich fat and protein contents alongside its abundance in LABs with biotechnological properties.
Fish gelatin‐pectin (GelExt/Pec) composite films incorporated with Mentha pulegium essential oil (MEO) and Lavandula angustifolia essential oil (LEO) at two concentrations (0.5% and 1.5%) were ...developed and their physicochemical, mechanical, and antimicrobial properties were determined. GelExt/Pec‐based film incorporated with 1.5% MEO (GelExt/Pec + 1.5% MEO) showed the highest antimicrobial activity against all bacterial strains tested. Incorporation of essential oils decreased significantly the tensile strength of all the films investigated. The film showing the best functional and antimicrobial properties (Gelext/Pec + 1.5% MEO) was used to prolong the shelf life of tilapia fillets under refrigeration. Control (unwrapped) and wrapped fillets were analyzed every 3 days in terms of microbiological (total viable count (TVC), psychrotrophic bacteria count (PC), lactic acid bacteria (LAB) and Enterobacteriaceae (ENT), and physicochemical parameters (total volatile base nitrogen TVB‐N and pH). Gelext/Pec + 1.5% MEO antimicrobial film retarded significantly (p < .05) the growth of TVC, LAB, PC, and ENT, throughout 12 days of storage compared with the control. Gelext/Pec + 1.5% MEO could be considered as an effective packaging to maintain the quality and extend the shelf life of tilapia fillets under refrigeration.
Legumes, native to the Mediterranean, harbor reservoirs of endophytes that help plants adapt to various environmental stresses. The current study was carried out to evaluate the plant growth ...characteristics and antifungal activity of root nodule endophytes as biocontrol agents and plant growth promoters. Eleven bacterial endophytes isolated from root nodules of Sulla flexuosa L. grown in Northwest Morocco were assessed for their plant growth-promoting (PGP), and antifungal properties. Four endophytic bacteria were selected for their efficiency in solubilizing inorganic phosphate. The selected strains were positive for more than 2 PGP traits, including indole acetic acid, ACC deaminase, siderophore, and ammonia production. The screening for lytic enzyme production revealed that all strains were capable of producing chitinase, cellulase, catalase, and protease, while the secretion of amylase and urease was not detected. The HFB11 was the only strain incapable of producing pectinase. In vitro experiments revealed the strains’ potential to withstand salt and drought stresses by being able to grow in high concentrations of NaCl and PEG. Based on 16S rRNA gene sequencing, the strains were identified as Enterobacter and Serratia. The antagonistic activity of the strains against Botrytis cinerea, Aspergillus ochraceus, and Fusarium oxysporum was detected and they were shown to inhibit the fungal growth with various percentages. The highest percentage of inhibition was observed for HFB3 against B. cinerea with 50% inhibition followed by HFB8 which was able to inhibit 47% of F. oxysporum’s growth. In contrast, a weak inhibition was observed against A. ochraceus. All these findings indicate that the chosen endophytes, halotolerant Serratia inhibens HFB8 and Enterobacter hormaechei HFB11, might be used as candidates for effective biocontrol and growth promotion of legumes.
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