Assessment of Bio-Deterioration in Dried Fig, Sesame, Pistachio, and Musk-Melon Seeds: A Storage Perspective

Mycobiota Isolation and Aflatoxin B1 Contamination in Fresh and Stored Sesame Seeds from Rainfed and Irrigated Zones of Punjab, Pakistan

Pistachio processing is one of the ways to increase the value added of pistachio. Production of pistachio butter is for this purpose. Pistachio butter is a paste form product that contain mainly milled, roasted pistachio kernel with sugar. The aim of this investigation is to produce pistachio butter using sunflower and sesame pastes. For this purpose, pistachio butter was formulated using sunflower and sesame pastes in two levels (10 and 20%). Rheological and organoleptic tests (from flavor, texture and color point of view) performed on the end products. The results were statistically analyzed by completely randomized Design and comparison between the means via Duncan's range test (5% level). The result of organoleptic test showed that the treatments 1, 2, 3 and 6 had higher scores. On the basis of organoleptic test, nutrition value as well as price product, suitable pistachio butter treatment was treatment 6. This formula contains 10% sunflower paste and 10% sesame paste.

Supercritical fluid extraction of oil from muskmelon (Cucumis melo) seeds

This paper provides data of investigation of fungal, aflatoxins M1 (AFM1) and B1(AFB1) contamination of three hundred and forty three samples of five different food commodities from three States in Nigeria. Maize samples from Niger (43) and Kogi (50) States and dried yam chips (50) from Niger State were purchased and assessed for fungal contaminants. Seventy (30 each from the maize samples and 11 from yam chips) of the two hundred and forty five fungi isolated from the maize and dried yam chips samples (77 and 151 from maize from Niger and Kogi respectively, and 17 from yam chips) were screened for their mycotoxin producing potentials in albino mice. One hundred samples of imported powdered milk marketed in Lagos metropolis were also analyzed for AFM1 using column chromatography for clean up and thin layer chromatography coupled with a densitometer equipped with winCATs soft ware for quantification. The Aflatoxin B1contents of fifty marketed samples each of beans and wheat from Minna were also determined using thin layer chromatography with visual estimation. Fusariumspecies, Aspergillus fumigatus and Aspergillus flavus were the major seed borne fungi in maize from the two States. While the predominant fungal contaminants of dried yam chips were Fusarium, Aspergillus and Mucor species. Toxicity screening results showed that 68.57% of the fungi tested were toxigenic and were mostly isolates of Aspergillus, Fusarium, Penicillium, Rhizopus and Mucor. AFM1was detected in 19 samples out of the 100 milk samples analyzed at levels ranging from 0.02 - 0.41 μg/kg. AFB1 was found in 29 out of the 50 beans (63.5 - 106.2μg/kg) samples analyzed while 54% of the 50 marketed wheat samples (102.9 - 198.4 μg/kg) were also contaminated with the toxin. While the AFM1 found in the milk samples were below the 0.5 μg/kg permitted by European Union, Codex Alimentarius Commission and National Agency for Food and Drug Administration and Control, Nigeria, the AFB1 levels in beans and wheat were above the permissible limits of these regulatory agencies (4 - 5 μg/kg). Key words: Fungi, aflatoxins, maize, yam, milk, beans, wheat.

Sesame is a significant oilseed crop cultivated extensively in the tropical and subtropical areas of India. Seed-borne pathogens are the most important biological constraints in seed production worldwide. Seed health testing to detect seed-borne pathogens is an important step in the management of crop diseases. In addition, it is also essential to adopt environmentally friendly strategy for preventing and managing seed-borne diseases. The main objectives of the present investigation including testing the seed health status of different sesame seed samples, evaluation the seed health testing methods, and assessing the efficacy of different biological agents against seed-borne pathogens and seed quality in sesame through seed biopriming and dry seed treatment. To find the mycoflora that was positively correlated with seeds, samples of sesame seeds were collected from farmers, research stations, and seed production plots. According to the findings, the most common types of fungi that are associated with sesame seeds are Macrophomina phseolina, Alternaria sesami, Aspergillus flavus, Aspergillus niger, Rhizopus sp., Curvularia sp., and Fusarium sp. Among the seed-borne fungi, the infection of M. phaseolina was observed highest in most of the sesame seed samples followed by A. sesami, A. flavus and A. niger. Various techniques used to detect seed mycoflora, the blotter technique was the most efficient method, with a maximum recovery of 45.1 %, followed by the potato dextrose agar (PDA) plate method (35.2 %), while the minimum recovery was observed in deep freezing blotter method (16.4 %). However, the detection of seed- borne pathogens of significance like A. sesami and Macrophomina M. phseolina was best in PDA plate method (9.82 and 14.2 %) followed by standard blotter method (7.9 and 11.8 %). Among the different bioprimed seeds individually and in combination, Bacillus subtilis (1%) alone primed seeds recorded lesser seed infection (0.66 %) and higher germination per cent (92 %) and seedling vigour (1186). When compared to dry seed treatment, sesame seeds primed with biocontrol agents generally showed lower seed infection (%) and higher seed quality parameters. The findings revealed the presence of several mycoflora in all sesame seed samples, and these seed mycoflora can be detected effectively by the standard blotter paper method and the PDA plate method. Furthermore, the biopriming technique has the potential to mitigate the detrimental impact of these microbes, thereby improving seed quality characteristics.

Melon (Citrullus colocynthis L.) is an important crop used mainly for soups in Nigeria. Egusi: as it is commonly called in Nigeria is contaminated by many fungal pathogens which reduce quality of seeds during storage. Use of botanicals can be a safe method to manage fungal contamination instead of chemicals which pose a threat to human health. Therefore, efficacy of Piper guineense, Xylopia aethiopica and Ocimum gratissimum on fungi in shelled Egusi seed kernels (EK) were evaluated. One market in each of six South-western Nigerian states where Egusi is sold was purposively selected in 2012 and 2013. Egusi kernels (1⁄2kg, n = 162) were purchased from selected traders for fungi isolation, identification and incidence (%) determination. Clean EK treated with botanical powder (10, 20 and 40 g kg–1) were inoculated with Aspergillus flavus, A. niger, A. tamarii, Rhizopus sp., Penicillium aurantiogriseum, P. citrinum and Fusarium solani bi-weekly for 14-week storage period to evaluate growth reduction (%). Control was inoculated with sterile distilled water. Aspergillus flavus, A. niger, A. tamarii, Penicillium citrinum, P. aurantiogriseum, Fusarium solani and Rhizopus sp. were frequently encountered in EK. Aspergillus (32.4±1.6%) was the most predominant fungus followed by Rhizopus (21.5±2.0%) in all States. Piper guineense (40 g kg–1), X. aethiopica (20 g kg–1) and O. gratissimum (10 g kg–1) powders significantly reduced aflatoxin contamination by 42.5%, 56.5% and 45.0%, respectively; fungi growths were progressively reduced by P. guineense (5.5-90.0%), X. aethiopica (6.7-100.0%) and O. gratissimum (7.4 66.7%) up to 12 weeks of storage. Egusi kernels were highly infected with postharvest fungi especially Aspergillus species. Xylopia aethiopica at 20 g kg–1, O. gratissimum (40.0%) and P. guineense (40.0%) reduced fungi growth on Egusi considerably and therefore could be used as a safe management option to mitigate storage fungi contamination in Egusi kernels.

Semipermeable cell walls or apoplastic "membranes" have been hypothesized to be present in various plant tissues. Although often associated with suberized or lignified walls, the wall component that confers osmotic semipermeability is not known. In muskmelon (Cucumis melo L.) seeds, a thin, membranous endosperm completely encloses the embryo, creating a semipermeable apoplastic envelope. When dead muskmelon seeds are allowed to imbibe, solutes leaking from the embryo are retained within the envelope, resulting in osmotic water uptake and swelling called osmotic distention (OD). The endosperm envelope of muskmelon seeds stained with aniline blue, which is specific for callose (beta-1,3-glucan). Outside of the aniline-blue-stained layer was a Sudan III- and IV-staining (lipid-containing) layer. In young developing seeds 25 d after anthesis (DAA) that did not exhibit OD, the lipid layer was already present but callose had not been deposited. At 35 DAA, callose was detected as distinct vesicles or globules in the endosperm envelope. A thick callose layer was evident at 40 DAA, coinciding with development of the capacity for OD. Removal of the outer lipid layer by brief chloroform treatment resulted in more rapid water uptake by both viable and nonviable (boiled) seeds, but did not affect semipermeability of the endosperm envelope. The aniline-blue-staining layer was digested by beta-1,3-glucanase, and these envelopes lost OD. Thus, apoplastic semipermeability of the muskmelon endosperm envelope is dependent on the deposition of a thick callose-containing layer outside of the endosperm cell walls.

The viability and vigor of osmotically primed (0.3 m KNO3, 6 days, 25C) and nonprimed `PMR 45' muskmelon (Cucumis melo L.) seeds were compared after storage for 9 years at <20C and 6% moisture content (MC, dry weight basis). Viability was compared at 20, 25, and 30C at water potentials of 0, -0.2, -0.4, -0.6, and -0.8 MPa and in soil. Additionally, stored primed and nonprimed seeds were either primed, aged (15% MC and 45C) for up to 8 days, or aged for 72 hours and primed. The force required to puncture 5-mm-long, micropylar seed pieces was measured using an Instron universal testing machine. Less force was required to puncture primed seed pieces at 0, 5, 15, 20, and 25 hours of imbibition, demonstrating that osmotic priming weakens the perisperm envelope tissue that the radicle must penetrate for germination to occur. In an earlier report, germination rate and final germination percentages were higher for osmotically primed seeds both in laboratory tests and field emergence studies conducted immediately after priming. After 9 years in storage, nonprimed seeds germinated to higher percentages in water at 30C and reduced water potential at all temperatures, while primed seeds germinated to higher percentages in water at 20 and 25C and exhibited a higher percentage of seedling emergence at a soil MC of 17%. Priming durations of ≤5 days had no effect on the viability, while longer durations decreased the viability of stored primed and nonprimed seeds. Priming generally decreased the log mean time to germination of stored nonprimed seeds but increased values for stored primed seeds. Controlled deterioration increased the log mean time to germination and decreased the viability of primed seeds faster than nonprimed seeds. Priming following controlled deterioration had no effect on nonprimed seeds and reduced the percent viability of primed seeds by 20%. Osmotic priming has a deleterious effect on the seed storage life of muskmelon seeds.

Myrothecium verrucaria (Albertini & Schwein.) Ditmar:Fr. was isolated from muskmelon (Cucumis melo L.) seeds of Charentais-T, a culti var used as a differential host with no resistance to Fusarium oxysporum f. sp. melonis races. A white floccose mycelial mat developed on melon seeds during incubation on moist blotters. Mycelia were mass transferred from melon seeds onto potato dextrose agar (PDA) medium. At 25°C in the dark, a mycelial mat with characteristic annelations of greenish-black sporodochia, without setae, was produced. Conidia (2 to 3 × 6 to 10 μm) were lemon shaped, with a typical conical mucous appendage at one end, which was visible with Loeffer's flagella stain (1). Based on these characteristics, the fungus was identified as M. verrucaria. For pathogenicity studies, surface sterilized seeds of C. melo cv. Charentais-T were coated with M. verrucaria conidia by gently rubbing the seeds on sporodochia produced on 15-day-old cultures on PDA. Once coated, seeds were plated onto water agar and on sterile moist blotters in 9-cm-diameter petri dishes. Plates were incubated at 28°C in the dark. Five seeds per plate and three plates per experiment were used. Experiments were replicated three times. Control seeds were plated without coating. After 7 days, on water agar, 90% of melon seeds failed to germinate while the remaining 10% produced young seedlings that died from root rot and necrotic lesions on the hypocotyl. After 12 days on moist blotters, 100% of the melon seedlings died, showing necrotic lesions on the hypocotyl and on the main root. The pathogen was reisolated from symptomatic melon seedlings. All control seeds germinated and grew into healthy seedlings. M. verrucaria, known to be a seed-borne pathogen, has been isolated from soil and plants worldwide (2). This is the first report of M. verrucaria pathogen on muskmelon. This fungus is not a serious concern when seeds are dressed with fungicides.

Sesame (Sesamum indicum) is usually contaminated with many fungi where some of them are mycotoxigenic causing economic and health problems. This study investigated the percentage composition of fungi contamination of sesame seeds in Benue state Nigeria. Using direct plating technique; the study revealed twelve species of fungi contamination in sesame seed obtained in Benue State. The percentage occurrence of fungal isolates shows that Aspergillus flavus and A. niger were found in all the locations and their occurrence was significantly different (P≤0.05). The percentage contamination of Sesame samples collected from Otukpo LGA has the highest fungal (23.35%) contamination and was significantly higher (P≤0.05) from samples of other places whereas Sesame contamination from Gboko was the least with total percentage of (12.05%). In conclusion, considering the benefits of sesame, it is recommended that several treatments should be applied to reduce the levels of contamination in sesame seeds before consumption utilization such as environmental conditions leading to fungal proliferation (a high temperature, humidity, poor soil fertility, drought and insect damage). Also poor harvesting practices, unsuitable storage conditions, improper transportation, marketing and processing should be discouraged.

Influence of tillage on soil physical properties and three varieties of sesame (Sesamum indicum L.) in Ogbomoso, southwestern Nigeria

Twenty-two seed samples of inodorous melons, collected from the areas of Peshawar, Swabi, Tordher, Fatu-chuk, Mardan, Karachi, Islamabad, Ghotki, and Mandibahauddin, yielded 75 species of 36 fungal genera, isolated through ISTA (International Seed Testing Association) techniques. The agar plate method was chosen as being best for the qualitative and quantitative isolation of fungi, followed by the standard blotter method. The agar plate method yielded 64 species of 29 genera, while the blotter method yielded 24 species belonging to 14 genera. The deep-freezing method yielded only 2 species belonging to 2 genera. Aspergillus niger , followed by A. flavus , Chaetomium globosum , and Rhizopus stolonifer were the most dominant fungi in all 3 methods used. Forty species belonging to 25 genera had not been previously reported from Pakistan. Seven seed samples, which were highly infected with fungi, were grown in test tube slants, included samples from Tordher (1), Ghotki (1), Mandibahauddin (1), Karachi (2), Islamabad (1), and Fatu-chuk (1). Aspergillus flavus was the most dominant fungi, causing pre-emergence rot of seedlings. Fusarium oxysporum caused 3.6 % of seedling deaths after 10 - 12 days of incubation. Seed samples from Islamabad, Mandibahauddin, and Swabi were highly infected with A. flavus . The level of aflatoxin B 1 estimated through CD-ELISA for the 3 samples was 32.64 ppb (Swabi), 11.48 ppb (Islamabad), and 7.30 ppb (Mandibahauddin), respectively, of which the seed sample from Swabi contained the highest level of aflatoxins. Surface sterilization of seeds with 1 % Calcium hypochlorite (Ca (OCl) 2 )greatlyreduced the incidence of both saprophytic and superficial pathogenic fungi. doi: 10.14456/WJST.2016.3

In vivo evaluation of two essential oil based botanical formulations (EOBBFs) for the use against stored product pathogens and pests, Aspergillus species and Callosobruchus species (Coleoptera: Bruchidae)

Rice anaerobic fermentation is a significant source of greenhouse gas (GHG) emissions, and in order to efficiently utilize crop residue resources to reduce GHG emissions, rice straw anaerobic fermentation was regulated using lactic acid bacteria (LAB) inoculants (FG1 and TH14), grass medium (GM) to culture LAB, and Acremonim cellulolyticus (AC). Microbial community, GHG emission, dry matter (DM) loss, and anaerobic fermentation were analyzed using PacBio single-molecule real-time and anaerobic fermentation system. The epiphytic microbial diversity of fresh rice straw was extremely rich and contained certain nutrients and minerals. During ensiling, large amounts of GHG such as carbon dioxide are produced due to plant respiration, enzymatic hydrolysis reactions, and proliferation of aerobic bacteria, resulting in energy and DM loss. Addition of FG1, TH14, and AC alone improved anaerobic fermentation by decreasing pH and ammonia nitrogen content (P < 0.05) and increased lactic acid content (P < 0.05) when compared to the control, and GM showed the same additive effect as LAB inoculants. Microbial additives formed a co-occurrence microbial network system dominated by LAB, enhanced the biosynthesis of secondary metabolites, diversified the microbial metabolic environment and carbohydrate metabolic pathways, weakened the amino acid metabolic pathways, and made the anaerobic fermentation cleaner. This study is of great significance for the effective utilization of crop straw resources, the promotion of sustainable livestock production, and the reduction of GHG emissions.IMPORTANCETo effectively utilize crop by-product resources, we applied microbial additives to silage fermentation of fresh rice straw. Fresh rice straw is extremely rich in microbial diversity, which was significantly reduced after silage fermentation, and its nutrients were well preserved. Silage fermentation was improved by microbial additives, where the combination of cellulase and lactic acid bacteria acted as enzyme-bacteria synergists to promote lactic acid fermentation and inhibit the proliferation of harmful bacteria, such as protein degradation and gas production, thereby reducing GHG emissions and DM losses. The microbial additives accelerated the formation of a symbiotic microbial network system dominated by lactic acid bacteria, which regulated silage fermentation and improved microbial metabolic pathways for carbohydrates and amino acids, as well as biosynthesis of secondary metabolites.

Comparison of dry matter losses and aflatoxin B1 contamination of paddy and brown rice stored naturally or after inoculation with Aspergillus flavus at different environmental conditions