Spoilage Molds Research Articles

Broad-spectrum antimicrobial activities of a food fermentate of Aspergillus oryzae.

The development of NP, a potent broad-spectrum antimicrobial, is a significant breakthrough in the ongoing challenge against microbial foodborne illnesses and the growing threat of antibiotic resistance. This food-grade culture broth of Aspergillus oryzae demonstrates exceptional broad-spectrum efficacy against a variety of harmful bacteria and fungi, including drug-resistant strains such as methicillin-resistant Staphylococcus aureus and prevalent food spoilage molds. NP exhibits strong bactericidal activity against various foodborne and ESKAPE pathogens, and strong antifungal activity against Penicillium species, Aspergillus fumigatus, and Candida albicans. The potent bactericidal and antifungal properties of NP are a result of its ability to disrupt microbial cell membranes leading to increased permeability. Furthermore, the genome-wide impact of NP on fungal gene expression and metabolic pathways underscores its comprehensive antimicrobial action, leading to transcriptomic and metabolic changes associated with cell death in A. fumigatus.

Characterizing the antioxidant and antifungal properties of nano-encapsulated pistachio hull extract in fenugreek seed gum to maintain the quality and safety of fresh pistachio.

The quality of pistachio, one of the export products of Iran, will be decreased during storage as a result of mold spoilage, toxins production, and oil oxidation. This study aimed to investigate the capability of pistachio hull extract (PHE) loaded in fenugreek seed gum (FSG):whey protein isolate (WPI) nanoemulsion to control oil oxidation, and fungi growth in fresh pistachio nut during storage at 4°C. The total anthocyanin and total phenolic content of the PHE were 125.44 μg/g and 675.18 mg/g, respectively. The DPPH radical scavenging activity of PHE at 100 ppm was higher than that of tert-butylhydroquinon (TBHQ). In comparison with other concentrations, 50 ppm showed the strongest antifungal activity against Aspergillus flavus, Aspergillus parasiticus, and Aspergillus nomius. All nanoemulsions have a mean size lower than 265 nm. The polydispersity index (PDI) of different nanoemulsions was lower than 0.3, and a negative zeta potential was observed. The encapsulation efficiency was higher than 67.0% and all nanoemulsions had spherical morphology. The pistachio nuts were coated with different coating solutions containing 0 and 100 ppm of PHE and stored at 4°C for 8 weeks. The results showed that the pistachio sample coated with a composite coating of WPI and FSG containing 100 ppm of PHE has a higher moisture content and lower changes in L*, a*, and b* indexes, oil oxidation, fungi development, and total mold and yeast count. This treatment exhibited higher overall acceptance than other samples at the end of storage time. The results of this study suggest the use of biodegradable coatings enriched with natural extracts that have high antioxidant and antifungal activities.

Use of Bacillus spp. as beneficial fermentation microbes in baking

The development of minimally processed baked goods is dependent on new “clean label” functional ingredients that allow substitution of additives without compromising quality. We investigated the use of fermentation with Bacillus spp. as a novel approach to improve bread quality. Bacillus velezensis FUA2155 and Bacillus amyloliquefaciens Fad WE ferments were prepared using white wheat flour, wheat bran or buckwheat, and were added at a level of 2.5–20 % to bread dough. Ropy spoilage of bread was controlled by sourdough addition at a level of 10 or 20 %. The volume of white wheat bread and wheat bran bread increased by 47.4 and 62.5 % respectively with 2.5 % Bacillus ferments. Bread shelf-life was prolonged by the Bacillus ferment only at higher dosages that also reduced bread volume. The use of unfermented or sourdough fermented buckwheat improved bread volume and delayed mould spoilage. The characterization of water-soluble polysaccharides from sourdoughs and Bacillus ferments revealed that solubilization of arabinoxylans contributed to the increase in volume after fermentation of wheat but not after fermentation of buckwheat. In conclusion, Bacillus fermentation can be used to improve bread quality, adding to the diversity of microbes that are suitable for baking applications.

Unveiling impact of word concepts on Enhancement or Reduction of Spoilage Molds growth and shelf life of strawberries

Aim: In the present study, the objective was to investigate the impact of written words on inhibiting the growth of molds in the cultivation medium and on strawberry fruit. Methods: Two pairs of opposite written words with positive or negative connotations (such as love-hate and peace-war) were selected to study their effects on the inhibition growth of two of the most common fruit molds (Aspergillus niger and Botrytis cinerea) at various incubation periods (ranging from 1 to 5 days) at 25°C. Results: The findings indicated that there were no statistically significant differences (P≥0.05) in the growth of both molds on the medium when exposed to words with opposing meanings. However, when strawberries were inoculated with the mold spores and subjected to written words with positive connotations, such as "love" and "peace," a significant reduction in mold growth was observed (P<0.05) compared to the control group. Furthermore, the presence of the word "love" resulted in the longest shelf life for strawberries contaminated with either A. niger or B. cinerea during cold storage period, with durations of 39 and 28 days, respectively. Conclusion: These findings shed light on unexplored aspects and propose novel perspectives regarding the potential use of written phrases and words to enhance food quality and mitigate fungal contamination in fruits and vegetable products.

Antifungal Properties of Ozone Treatment against P. citrinum and R. stolonifera in Fresh-Peeled Garlic

Garlic is susceptible to decay and presents a potential vehicle for foodborne disease transmission. Ozone treatment has proven to be an effective and innoxious method to provide bacterial resistance in this globally popular pungent vegetable. This study was conducted to evaluate the effects of different ozone treatments (differing in terms of concentration, treatment time and temperature) against Penicillium citrinum and Rhizopus stolonifer in spoiled fresh-peeled garlic. The results have shown that the most inhibitory conditions for in vitro treatments were achieved with an ozone concentration, treatment time and temperature of 6 ppm, for 20 min at 20 °C, respectively, on the P. citrinum and 8 ppm, for 20 min at 25 °C, respectively, on the R. stolonifer. The optimum in vivo ozone treatment conditions for fresh-peeled garlic inoculated with the same two kinds of spoilage molds remained the same for both, consisting of an ozone concentration of 6 ppm, a time of 15 min and a temperature of 20 °C. Following these ozone treatments, the total number of colonies of yeast and mold, as well as the incidence, lesion diameter and depth of spoilage in the fresh-peeled garlic was significantly reduced during storage, with improved bactericidal inhibition effects. In conclusion, this study showed that ozone treatment effectively inhibits the growth of spoilage molds, destroys cell structures, and affects the metabolic and physiological processes of P. citrinum and R. stolonifer. Thus, it provides a protective shield and extends the shelf life of fresh-peeled garlic.

Growth/no-growth models of propionic and sorbic acid for bread and cake moulds

Propionic and sorbic acid are very effective weak-organic acid preservatives in bakery products. Their pH-dependent antifungal activity, the role of undissociated acid and the importance of the aqueous phase was studied. Besides looking for new natural preservation techniques the gain of further knowledge on their activity is still highly relevant to tackle the problem of food waste. In this study, the susceptibility of spoilage moulds for propionic (PA) and sorbic acid (SA) was tested in-vitro and in bread and cake. Aspergillus niger, Aspergillus montevidensis, Aspergillus ruber, Cladosporium ramotenellum, Penicillium brevicompactum and Penicillium roqueforti were subjected to PA and SA, both through macrodilution on malt extract agar (MEA) plates with adjusted aw (0.93, 0.95, 0.97), pH (5, 5.5, 6.0), acid (max. 2000 mg/L MEA), and through validation in wheat bread (max. 2901 mg PA/kg) and (lemon) cake (max. 1988 mg SA/kg). The undissociated acid concentrations (CHA) were estimated using either the Henderson-Hasselbalch (HH) equation or two modified HH equations. The influence of the food matrix (liquid oil, water, pH, aw), partitioning coefficient of the acids and spoilage fungi were evaluated and results were compared with in-vitro predictive models. In bread, the regular HH eq. proved to have good predictive power of CHA, whereas in cake a modified HH eq. (model 2) had better performance due to the inclusion of potential loss of CHA in the oil phase of complex food systems. The minimal inhibitory concentration (MIC) of PA in bread, after 30 days, was higher than 2901 mg/kg bread due to the strong resistance of P. brevicompactum, P. roqueforti and A. montevidensis. MIC of SA in lemon cake was 1429 mg SA/kg (pH 5.2), whereas in standard cake with pH 7.2, the max. level of 1988 mg SA/kg was insufficient for postponing mould growth to 30 days. The pH of cake had no influence on MIC of SA against A. niger and A. rubrum, whereas this effect was seen for C. ramotenellum, P. brevicompactum and P. roqueforti.

Photosensitization can be an effective risk-reduction strategy against the post-baking mold spoilage of bread

Photosensitization was developed as a risk-reduction strategy against the contamination by environmental mold spores during the bread cooling phase. Two food-grade photosensitizers -chlorophyllin (CHL) and riboflavin (RBF), were used to evaluate the effect of visible (blue) LED illumination against three common bread spoilage molds. Aided by CHL, 405 nm LEDs inactivated Rhizopus stolonifer and Penicillium expansum by 77.4 ± 3.3% and 52.1 ± 7.3% respectively in 30 min on dichloran rose bengal chloramphenicol agar. These reductions were much higher than the corresponding reductions observed with food-grade RBF and 445 nm LEDs - 22.8 ± 3.2% and 45.5 ± 5.9%, indicating that CHL-based photosensitization was more effective as an intervention than RBF-based photosensitization. When the three molds were illuminated on bread after spraying CHL and spot-inoculation, their populations were reduced by 51–58%. CHL-based photosensitization was observed to retain the texture and moisture of the bread samples, but had a statistically significant impact on their colour. The results of this study suggest that CHL-based photosensitization can be developed as a risk reduction method to prevent the spoilage of bread.

Exploring yeast-based microbial interactions: The next frontier in postharvest biocontrol.

Fresh fruits and vegetables are susceptible to a large variety of spoilage agents before and after harvest. Among these, fungi are mostly responsible for the microbiological deteriorations that lead to economically significant losses of fresh produce. Today, synthetic fungicides represent the first approach for controlling postharvest spoilage in fruits and vegetables worldwide. However, the emergence of fungicide-resistant pathogen biotypes and the increasing awareness of consumers towardthe health implications of hazardous chemicals imposed an urgent need to reduce the use of synthetic fungicides in the food supply; this phenomenon strengthened the search for alternative biocontrol strategies that are more effective, safer, nontoxic, low-residue, environment friendly, and cost-effective. In the last decade, biocontrol with antagonistic yeasts became a promising strategy to reduce chemical compounds during fruit and vegetable postharvest, and several yeast-based biocontrol products have been commercialized. Biocontrol is a multipartite system that includes different microbial groups (spoilage mold, yeast, bacteria, and nonspoilage resident microorganisms), host fruit, vegetables, or plants, and the environment. The majority of biocontrol studies focused on yeast-mold mechanisms, with little consideration for yeast-bacteria and yeast-yeast interactions. The current review focused mainly on the unexplored yeast-based interactions and the mechanisms of actions in biocontrol systems as well as on the importance and advantages of using yeasts as biocontrol agents, improving antagonist efficiency, the commercialization process and associated challenges, and future perspectives.

Mycobiota of Potato-Cereal Soft Wraps and the Production Facility.

The aim of this study was to investigate the mycobiota of potato-cereal soft wraps and in the processing area. Potato-cereal soft wraps are cooked, cold-stored and mashed potatoes that are kneaded together, usually with wheat flour, to form dough. In order to identify the main spoilage mould of this product, 150 visible mould colonies from mouldy wraps were identified. Five different mould species were isolated; Aspergillus niger, Penicillium brevicompactum, Penicillium commune, Penicllium corylophilum and Pencillium discolor. The dominating spoilage mould was Penicillium commune with 83.9% of the colonies. In order to study the mycobiota of the production area, 271 samples of air and surfaces were collected. In total, 647 mould colonies were isolated from air and surface samples. The mycobiota of air consisted of 27 different species within 9 different genera, and the mycobiota of surfaces consisted of 14 species within 4 different genera. Penicllium species were the dominating genera both in air and on surfaces, and Penicillium commune was the dominating species in the processing environment as well. Penicillium commune was found in the bakery and also in other production rooms. Spores from the flour and from soil on potatoes can disperse in the air as aerosols and may contaminate the wraps after baking when the product is cooled before packaging.

Evaluation of Spoilage Mould and Nutrient Composition of Oil Palm Fruit

Research on the nutrient composition of palm fruit and the associated spoilage mould was carried out in Plant Science and Biotechnology and Microbiology Departments in Rivers State University. Fresh palm fruit was purchased from mile 3 market in Port Harcourt. The fruits were washed and sent for nutrient analysis while the other fruits were kept until visible symptoms of diseases were noticed. Proximate analysis revealed that the palm fruit had a moderate moisture content (9.3%), high lipid content (31.95%), and high fibre content (35.15%), carbohydrate and protein values were (12.45%) and (5.5%) respectively. The vitamins composition recorded (151.01%) for Vitamin A and (45.15%) for Vitamin B. Phytochemicals were also present in appreciable amounts. Carotenoids recorded (33.45%), Polyphenols (7.88%). Oil characteristics value showed that saponification had the highest value (201.75%) while peroxide had the least value of (1.93%). Saturated fatty acids were palmitic acid (44.05%), oleic acid (39.24%), and linoleic acid (10.12%). Rhizopus was the only fungal pathogen identified in this study.

Multifunctional food packaging materials: Lactoferrin loaded Cr-MOF in films-based gelatin/κ-carrageenan for food packaging applications

In this study, antimicrobial biocomposite films based on gelatin–κ-carrageenan (Gκ) with 1, 2 and 4 % lactoferrin (L) loaded chromium-based metal–organic frameworks (L@Cr-MOFs) nanoparticles were synthesized by casting methods. The addition of L loaded Cr-MOFs into Gκ based films increased elongation at break from 2.19 to 14.92 % and decreased the tensile strength from 65.1 to 31.22 MPa. L@Cr-MOFs addition reduced swelling index (from 105 to 70.8 %), water solubility (from 61.3 to 34.63 %) and water vapor permeability (from 2.46 to 2.19 × 10−11 g. m/m2. s). When the additional amount was 4 wt%, the Gκ/L@Cr-MOFs films showed antibacterial effects against Escherichia coli and Staphylococcus aureus with the inhibition zone of 19.7 mm and 20.2 mm, respectively. In addition, strawberries preservation trial shown that the Gκ/L@Cr-MOFs films delayed the growth of spoilage molds on the surface of fruits. This research indicated that Gκ/L@Cr-MOFs are promising active packaging materials for the preservation of perishable fruits.

Antifungal activity of wheat-flour sourdough (Type II) from two different Lactobacillus in vitro and bread

This study aims to evaluate the antifungal capacity and chemical properties of the aqueous extracts (AE) obtained from the fermentation with Lactobacillus acidophilus NRRL B-4495 or L. casei 21/1 of wheat flour (poolish-type sourdough). The antifungal activity of poolish-type sourdoughs was tested against bread spoilage molds (Penicillium chrysogenum, and P. corylophilum) in vitro and bread. In addition, the physicochemical and sensory properties of bread formulated with the poolish-type sourdoughs were assessed. The AEs were obtained by separating the poolish supernatant at the end of fermentation (24, 48, or 72 h). Adding L. acidophilus or L. casei affects the sourdoughs’ pH and titratable acidity (TA), wherein the poolish added with L. casei presented a lower pH and higher acidity. HPLC identified mainly lactic acid in a concentration between 1 and 2% for the sourdoughs fermented with L. acidophilus, while for the poolish fermented by L. casei, lactic acid (1–2%) and acetic acid were identified (0.1–0.2%). Concentrations between 25 and 50% of AEs decreased the radial growth rate of P. crysogenum and P. corylophilum; in particular, the AEs obtained with L. acidophilus showed an effect on the growth of both molds. Bread added with sourdoughs fermented with Lactobacillus had an increase in shelf life compared to bread without them. There was an effect of the addition of poolish sourdoughs on the bread's physicochemical, quality, and sensory properties. But, incorporating L. acidophilus NRRL B-4495 or L. casei 21/1 into poolish-type sourdoughs can be an alternative as natural antifungal agents, useful for the bakery industry.

Utilization of edible coating based on quince seed mucilage loaded with thyme essential oil: Shelf life, quality, and ACE-inhibitory activity efficiency in Kaşar cheese

Edible coatings offer many advantages in cheese coating for prolonging the shelf life and improving quality properties. Mould spoilage that occurs during ripening is one of the most important issues in Kaşar cheese. The current study focused on the effects of an edible coating solution based on quince seed mucilage (QSM) containing thyme oil (TO) in different ratios, on the surface moulding of Kaşar cheese and evaluated the physicochemical, microbiological, textural, and proteolysis characteristics of Kaşar cheese throughout the 120 days of ripening. Also, the effect of edible coating on the in-vitro Angiotensin-converting enzyme (ACE)-inhibitory activities of pH 4.6-soluble extracts of Kaşar cheeses was investigated. Results showed that the coating of Kaşar cheese with QSM and the increased levels of thyme oil significantly suppress mould growth throughout the ripening. Until 120th days of ripening, counts of yeasts and moulds were lower <2 log cfu g−1 in coated cheese sample with QSM containing 2% TO. Coating with QSM caused an increase in moisture loss compared to vacuum-packed cheeses, however, didn't change the normal ripening conditions such as microbiological, chemical, textural, and proteolysis properties of Kaşar cheese. As the ripening progressed, ACE-inhibitory activity increased in all samples, with the highest inhibition in vacuum-packed and coated cheeses. Overall, it was determined that the QSM coating showed good potential as a coating material for the protection of cheese shelf life and quality as well as for enhancing ACE-inhibitory activity.

A functional intact SUMOylation machinery in Aspergillus flavus contributes to fungal and aflatoxin contamination of food

SUMO adducts occur in Aspergillus flavus, and are implicated in fungal biology, while the underlying mechanism and the SUMOylation apparatus components in this saprophytic food spoilage mould, remain undefined. Herein, genes encoding SUMOylation cascade enzymes in A. flavus, including two heterodimeric SUMO E1 activating enzymes, a unique SUMO E2 conjugating enzyme, and one of SUMO E3 ligases, were identified and functionally analyzed. Global SUMO adducts immunoassay, multiple morphological comparison, aflatoxin attributes test, fungal infection and transcriptomic analyses collectively revealed that: E1 and E2 were essential for intracellular SUMOylation, and contributed to both stress response and fungal virulence-related events, including sporulation, colonization, aflatoxins biosynthesis; the primary E3 in this fungus, AfSizA, might serve as the molecular linkage of SUMOylation pathway to fungal virulence rather than SUMOylation-mediated stress adaptation. These findings demonstrated that SUMOylation machinery in A. flavus was functionally intact and contributed to multiple pathobiological processes, hence offering ideas and targets to control food contamination by this mycotoxigenic fungus.

Machine olfaction discrimination of Spanish-style green olives inoculated with spoilage mold species

As an alternative to traditional sensory analysis evaluation, machine olfaction represents a valuable tool for detecting incipient defects caused by microorganisms. For this purpose, different strains of spoilage molds were inoculated into Spanish-style table olives and the effect on their sensory quality and volatile profile were analyzed using an electronic nose (E-nose). The main defects obtained for the different inoculated microorganisms associated with abnormal fermentation were mold and humidity. A total of 36 volatile compounds were identified and classified into phenolics, alcohols and carboxylic acids, while minor ones included derivatives of acids and oxygenated compounds. In general, a decrease in the concentrations of acetic acid, phenolic compounds and creosol was observed in olives inoculated with mould strains. However, propanoic acid, 2-methoxy-phenol, 2,4-dimethyl-heptane, among others, increased after mold inoculation. Sensorial and volatile compound analysis showed the table olives inoculated with the strains of Aspergillus flavus A.F.18 and Penicillium expansum P.E.20 to be the most altered. The E-nose data were able to classify the inoculated olives into different categories and distinguish them from the control treatment, regardless the intensity of the defect. The principal component analysis (PCA) of table olives inoculated showed that 70.23% of the total variance of data was explained by PC1 and 23.27% by PC. The sum of the elements of the diagonal of the confusion matrix gives the percentage of success in discrimination of 95.5%. Therefore, these results show the capacity and precision of E-nose to discriminate between the alterations caused by different mold strains.

The potential of UVC decontamination to prolong shelf-life of par-baked bread.

The effect of UVC (254 nm) treatment on the mould-free shelf-life of par-baked wholemeal, rye and six-grain bread was examined. Currently, these breads are par-baked, wrapped in high-density polyethylene (HDPE)-foil and transported or stored at room temperature for a couple of days before being full-baked and sold/consumed. Generally, after five days, these breads show signs of mould spoilage. A shelf-life increase in one or more days would already offer immense economical and logistic benefits for the baker or retailer. In this study, the parameters fluence rate (irradiation intensity), fluence (UV dose), distance to the UV-lamp (DTL) and number of layers of a common wrapping HDPE-foil (20 µm) were diversified. The breads were subjected to a UVC treatment (0-2502 mJ/cm²), packed and stored at room temperature for a period of 15 days (21.5 ± 0.8 °C). Similar as for the breads, agar plates with mould spores of Aspergillus niger, Aspergillus montevidensis and Penicillium roqueforti were UVC treated (0-1664 mJ/cm²) and checked daily for visible mould growth during 15 days (25 °C). Aspergillus niger showed the strongest resistance towards UVC, a fluence of 800 mJ/cm² was needed to inhibit growth during 15 days of storage, whereas for P. roqueforti and A. montevidensis, respectively, UV levels of 291 and 133 mJ/cm² were found sufficient. Furthermore, the shelf-life of wholemeal, rye and six-grain bread can be prolonged from 5 to 6, 8 and 9 days, respectively, using 2502 mJ/cm². The effect of higher UVC dosage on shelf-life reached a maximal level and was strongly impacted by the wide spread on data of mould-free shelf-life. The main factors influencing the potential of UV decontamination were the rough bread surface, differences in DTL, the possibility of post-contamination and UV permeability of packaging materials.

Prevention of mold spoilage and extend the shelf life of bakery products using modified mixed nano fermentate of Lactobacillus sp.

Fungal growth and mycotoxin production is the major economic importance in bakery products during manufacturing and storage. So, the present study aimed to prepare chitosan loaded mixed nano-fermentate of three Lactobacillus sp. [L. plantarum, L. helveticus and L. rhamnosus (PHR)] to be used as bio-preservatives in pan bread and cupcake. PHR-nanofermentate were applied in bread samples during mixing the ingredient, injected in bread loaves at the end of fermentation or added as coating materials after baking. Cupcake samples were treated by PHR-nanofermentate during mixing the ingredients or as coating materials after baking. Baking quality, color parameters, sensory properties and mold count of bread and cupcake samples were performed. Bread sample coated with PHR- nanofermentate after baking ranked the highest between the treated samples. Cake samples treated with PHR- nanofermentate during mixing step had higher scores for all sensory attributes compared to the coated cake, except the texture and appearance parameters. PHR-nanofermentate resulted in more effective disappeared mold counts at the end of shelf life for bread and cake. In conclusion, PHR-nanofermentate achieved the intended galas as antimicrobial agent and prolonged the shelf-life, regardless the addition method, in chemically leavened products. However, its addition method to bread and other baked products which utilize baker’s yeast as a leavening should be considered. Finally, this study demonstrates that "PHR" is a good product for the bio-preservation of food.

Proteomics as a New-Generation Tool for Studying Moulds Related to Food Safety and Quality

Mould development in foodstuffs is linked to both spoilage and the production of mycotoxins, provoking food quality and food safety concerns, respectively. The high-throughput technology proteomics applied to foodborne moulds is of great interest to address such issues. This review presents proteomics approaches useful for boosting strategies to minimise the mould spoilage and the hazard related to mycotoxins in food. Metaproteomics seems to be the most effective method for mould identification despite the current problems related to the bioinformatics tool. More interestingly, different high resolution mass spectrometry tools are suitable for evaluating the proteome of foodborne moulds able to unveil the mould's response under certain environmental conditions and the presence of biocontrol agents or antifungals, being sometimes combined with a method with limited ability to separate proteins, the two-dimensional gel electrophoresis. However, the matrix complexity, the high ranges of protein concentrations needed and the performing of multiple steps are some of the proteomics limitations for the application to foodborne moulds. To overcome some of these limitations, model systems have been developed and proteomics applied to other scientific fields, such as library-free data independent acquisition analyses, the implementation of ion mobility, and the evaluation of post-translational modifications, are expected to be gradually implemented in this field for avoiding undesirable moulds in foodstuffs.

Inhibition of individual and combination of cell free supernatants of phenyllactic acid, pediocin‐ and nisin‐producing lactic acid bacteria against food pathogens and bread spoilage molds

AbstractConsumer demand has led to an increase in the use of natural antimicrobials for baked good preservation. In this study, the cell‐free culture supernatants of three antagonistic bacterial strains were tested, and their individual and combined antimicrobial effects on Escherichia coli, Bacillus cereus, Aspergillus neoniger, and Penicillium roqueforti were examined. The mixture of phenyllactic acid and pediocin with ethylenediaminetetraacetic acid (EDTA) exhibited a strong inhibitory effect on E. coli growth (RIA 85%). Nisin mixed with phenyllactic acid or pediocin with EDTA exhibited a strong inhibitory effect on B. cereus growth with RIA 85% and 80%, respectively. Phenyllactic acid had a stronger inhibitory effect on P. roqueforti than on A. neoniger at 50 mg/ml MIC. The antipathogenic effects of phenyllactic acid, nisin, and pediocin (alone or in combination, with or without adjuncts) were stronger than their mold‐controlling effects. A combination of such biopreservatives with EDTA is a suitable alternative to the preservatives used to improve the shelf life of perishable food products.

Nutrient Composition of Lasianthera africana (NKANKA) and its Spoilage Moulds

The research on the nutrient composition of Lasianthera africana (Nkanka) and its spoilage moulds was carried out in the Department of Plant Science and Biotechnology Rivers State University Portharcourt. The nkanka leaves were purchased from Mile 3 Market in Portharcourt and was analysed in the laboratory of of Plant Science and Biotechnology, Rivers State University. The results of the proximate analysis of Lasianthera africana leaves revealed that the leaves are rich in moisture (65.45±0.07%) ash (4.515±0.01%), lipid (3.515±0.02%) fibre (6.48±0.06%), carbohydrate (3.34±0.07%) and protein (16.70±0.07%) respectively. Mineral assessment revealed the presence of Calcium, Iron, Magnesium, Phosphorus, Potassium, Sodium and vitamin C, A and B1. Phytochemical composition showed the presence of Glycoside, Oxalate, saponins, tannins, carotenoid, polyphenol, flavonoid and lignant. The fungal characterization produced three organisms viz; Aspergillus niger, Rhizopus sp, and Mucor sp with perentage incidences of 60% and 20% respectively. In conclusion, lasianthera africana leaves should be regularly consumed as they are used for the treatment of diarrhoea, dysentry, stomach troubles, ulcers and diabetes and also they are prone to fungal contaminations. Therefore, proper care should be taken during harvest and storage to reduce contamination