Functional Properties of Antimicrobial Neem Leaves Extract Based Macroalgae Biofilms for Potential Use as Active Dry Packaging Applications

Abstract

Antimicrobial irradiated seaweed–neem biocomposite films were synthesized in this study. The storage functional properties of the films were investigated. Characterization of the prepared films was conducted using SEM, FT-IR, contact angle, and antimicrobial test. The macroscopic and microscopic including the analysis of the functional group and the gas chromatography-mass spectrometry test revealed the main active constituents present in the neem extract, which was used an essential component of the fabricated films. Neem leaves’ extracts with 5% w/w concentration were incorporated into the matrix of seaweed biopolymer and the seaweed–neem bio-composite film were irradiated with different dosages of gamma radiation (0.5, 1, 1.5, and 2 kGy). The tensile, thermal, and the antimicrobial properties of the films were studied. The results revealed that the irradiated films exhibited improved functional properties compared to the control film at 1.5 kGy radiation dosage. The tensile strength, tensile modulus, and toughness exhibited by the films increased, while the elongation of the irradiated bio-composite film decreased compared to the control film. The morphology of the irradiated films demonstrated a smoother surface compared to the control and provided surface intermolecular interaction of the neem–seaweed matrix. The film indicated an optimum storage stability under ambient conditions and demonstrated no significant changes in the visual appearance. However, an increase in the moisture content was exhibited by the film, and the hydrophobic properties was retained until nine months of the storage period. The study of the films antimicrobial activities against Staphylococcus aureus (SA), and Bacillus subtilis (BS) indicated improved resistance to bacterial activities after the incorporation of neem leaves extract and gamma irradiation. The fabricated irradiated seaweed–neem bio-composite film could be used as an excellent sustainable packaging material due to its effective storage stability.

Comparative bioactive compounds and fourier transform infrared spectroscopic evaluation of Azadirachta indica extracts and its potential as bio-fungicides against plant pathogenic fungi

“…The 1087.21 cm -1 wave length (Figure 4) have a C-O-C stretch (dialkyl), C-O stretch a vibration type and assigned functional group was ether and alcohol. The C-H stretching vibration modes in the hydrocarbon chains were found at 2900 cm -1 peak values (Oyekanmi et al, 2021). The peak values pointed out the occurrence of OH connecting vibrations from minor phenols, alcohol primer, alkene, C=C aromatic, carboxylic acid groups and phenolic groups that assigned (Vijayarathna and Sasidharan, 2012).Whereas, the peaks values at 1734 cm -1 matching to the stretching vibrations of the C=O in carboxylic acids, aldehydes and ketones (Oyekanmi et al, 2021).…”

“…The C-H stretching vibration modes in the hydrocarbon chains were found at 2900 cm -1 peak values (Oyekanmi et al, 2021). The peak values pointed out the occurrence of OH connecting vibrations from minor phenols, alcohol primer, alkene, C=C aromatic, carboxylic acid groups and phenolic groups that assigned (Vijayarathna and Sasidharan, 2012).Whereas, the peaks values at 1734 cm -1 matching to the stretching vibrations of the C=O in carboxylic acids, aldehydes and ketones (Oyekanmi et al, 2021). Carboxylic acid esters reported maximum antifungal activities against Aspergillus niger, Candida albicans and Cryptococcus neoformans.…”

“…Every derivatives of carboxylic acid ester displayed maximum fungicidal activities as compared to fluconazole (Nam et al, 2004). The absorption bands of neem leaves at 1641 cm -1 was designated to the amide C=O connected to the occurrence of group of -COOH and the absorption bands at 1384 cm -1 were presented to the frequency stretching that comes from the C-O bonds of acetyl esters, C=O, CH 2 wagging and C-H stretching respectively (Oyekanmi et al, 2021). The 1600 (cm -1 ) wave length might be ascribed to C=C stretch (alkenes) and 1400 cm -1 band might be recognized as alkenes with C-O-C stretch and C-H in-plane bend.…”

“…These functional groups reported antibacterial and antifungal potential (Basir and Javid, 2013;Javid et al, 2015). Although several studies have evaluated the phytochemicals, FTIR and antimicrobial activities of neem extracts against a broad range of pathogens (Ali et al, 2022;Amadioha, 1999;Chukwuma et al, 2018;Govindachari et al, 1998;Khanal, 2021;Khajista, 2013;Lethika et al, 2013;Nwali et al, 2018;Oyekanmi et al, 2021), but the antifungal activity against the plant pathogenic fungi and FTIR measurements together of neem extracts remains elusive. The current study was aim to find a plant product, which can be used as a substitute of commercially available chemical fungicide.…”

The Antimicrobial Potential of the Neem Tree Azadirachta indica

“…In the last couple of years, several groups have shown that food preservation films that are made from polyethylene or sustainable materials such as seaweed can be manufactured to incorporate neem leaf extracts, neem oil, and other plant-based products (e.g., turmeric and curcumin) ( Ahmed et al, 2022 ). The resulting composite films are shelf-stable, block ultraviolet light, and have increased antifungal and antibacterial activities against C. albicans and a wide range of Gram-negative and Gram-positive organisms, including E. coli , S. aureus , Pseudomonas aeruginosa , and Bacillus subtilis ( Sunthar et al, 2020 ; Uthaya Kumar et al, 2020 ; Oyekanmi et al, 2021 ; Subbuvel and Kavan, 2021 ). Furthermore, the ability of A. indica to prevent activity of food-spoiling fungi is evident by several recent reports that outline the following: 1) the ability of neem oil to prevent the growth of the grape product-spoiling species Aspergillus carbonarius and to inhibit the production of mycotoxin by strains of this fungus ( Rodrigues et al, 2019 ), 2) the ability of neem leaves to prevent the production of aflatoxins by Aspergillus parasiticus during long-term storage of rice, wheat, and maize ( Sultana et al, 2015 ), 3) the ability of neem seed methanol and ethanol extracts to inhibit Aspergillus flavus and A. parasiticus by 10% in the context of maize storage ( An et al, 2019 ), 4) the ability of multiple neem seed, bark, and leaf extracts to inhibit the growth of three major potato-spoiling fungi, Aspergillus niger , Fusarium oxyporium , and Pythium spp., by 72–100% ( Ezeonu et al, 2019 ), and 5) the ability of aqueous neem leaf extract to inhibit growth of A. niger and A. parasiticus , as well as to detoxify aflatoxin B1 and ochratoxin A in vivo ( Hamad et al, 2021 ).…”