Bhanu Prakash

Chemical profile, antifungal, antiaflatoxigenic and antioxidant activity of Citrus maxima Burm. and Citrus sinensis (L.) Osbeck essential oils and their cyclic monoterpene, dl-limonene

The study deals with antifungal, antiaflatoxigenic and antioxidant activity of Citrus maxima and Citrus sinensis essential oils (EOs) and their phytochemical composition. The EOs were obtained by hydrodistillation and their chemical profile was determined through GC and GC-MS analysis. Both the EOs and their 1:1 combination showed broad fungitoxic spectrum against different food contaminating moulds. The EOs and their combination completely inhibited aflatoxin B(1) (AFB(1)) production at 500 ppm, whereas, DL-limonene, the major component of EOs showed better antiaflatoxigenic efficacy even at 250 ppm. Both the oils exhibited antioxidant activity as DPPH free radical scavenger in dose dependent manner. The IC(50) for radical scavenging efficacy of C. maxima and C. sinensis oils were to be 8.84 and 9.45 microl ml(-1), respectively. The EOs were found non-mammalian toxic showing high LD(50) for mice (oral, acute). The oils may be recommended as safe plant based antimicrobials as well as antioxidants for enhancement of shelf life of food commodities by checking their fungal infestation, aflatoxin production as well as lipid peroxidation.

Efficacy of chemically characterized Piper betle L. essential oil against fungal and aflatoxin contamination of some edible commodities and its antioxidant activity.

The study investigates fungal contamination in some dry fruits, spices and areca nut and evaluation of the essential oil (EO) of Piper betle var. magahi for its antifungal, antiaflatoxigenic and antioxidant properties. A total of 1651 fungal isolates belonging to 14 species were isolated from the samples and Aspergillus was recorded as the dominant genus with 6 species. Eleven aflatoxin B(1) (AFB(1)) producing strains of A. flavus were recorded from the samples. Eugenol (63.39%) and acetyleugenol (14.05%) were the major components of 32 constituents identified from the Piper betle EO through GC and GC-MS analysis. The minimum inhibitory concentration (MIC) of P. betle EO was found 0.7 microl/ml against A.flavus. The EO reduced AFB(1) production in a dose dependent manner and completely inhibited at 0.6 microl/ml. This is the first report on efficacy of P. betle EO as aflatoxin suppressor. EO also exhibited strong antioxidant potential as its IC(50) value (3.6 microg/ml) was close to that of ascorbic acid (3.2 microg/ml) and lower than that of the synthetic antioxidants such as butylated hydroxytouene (BHT) (7.4 microg/ml) and butylated hydroxyanisole (BHA) (4.5 microg/ml). P. betle EO thus exhibited special merits possessing antifungal, aflatoxin suppressive and antioxidant characters which are desirable for an ideal preservative. Hence, its application as a plant based food additive in protection and enhancement of shelf life of edible commodities during storage and processing is strongly recommended in view of the toxicological implications by synthetic preservatives.

Antifungal and antiaflatoxigenic properties of Cuminum cyminum (L.) seed essential oil and its efficacy as a preservative in stored commodities.

The study reports potential of Cuminum cyminum (cumin) seed essential oil (EO) as a plant based shelf life enhancer against fungal and aflatoxin contamination and lipid peroxidation. The EO showed efficacy as a preservative in food systems (stored wheat and chickpeas). A total of 1230 fungal isolates were obtained from food samples, with Aspergillus flavus LHP(C)-D6 identified as the highest aflatoxin producer. Cumin seed EO was chemically characterized through GC-MS where cymene (47.08%) was found as the major component. The minimum inhibitory concentration and minimum aflatoxin inhibitory concentration of EO were 0.6 and 0.5 μl/ml respectively. The EO showed toxicity against a broad spectrum of food borne fungi. The antifungal action of EO on ergosterol content in the plasma membrane of A. flavus was determined. The EO showed strong antioxidant potential having IC50 0.092 μl/ml. As a fumigant in food systems, the EO provided sufficient protection of food samples against fungal association without affecting seed germination. In view of the antifungal and antiaflatoxigenic nature, free radical scavenging potential and efficacy in food system, cumin seed EO may be able to provide protection of food commodities against quantitative and qualitative losses, thereby enhancing their shelf life. The present investigation comprises the first report on antifungal mode of action of cumin seed EO and its efficacy as fumigant in food systems.

Safety assessment of Zanthoxylum alatum Roxb. essential oil, its antifungal, antiaflatoxin, antioxidant activity and efficacy as antimicrobial in preservation of Piper nigrum L. fruits

The investigation deals with antifungal, antiaflatoxin and antioxidant efficacy of Zanthoxylum alatum Roxb. essential oil (EO), its two major constituents and their comparison with five commonly used organic acid preservatives. The chemical profile of EO, characterized through GC and GC-MS analysis, revealed linalool (56.10%) and methyl cinnamate (19.73%) as major components. The EO, linalool and methyl cinnamate completely inhibited the growth of a toxigenic strain of A. flavus (LHP-10) as well as aflatoxin B(1) secretion at different concentrations. Methyl cinnamate was found to be more efficacious than EO, linalool and five organic acid preservatives, showing antifungal and antiaflatoxigenic efficacy at a low concentration (0.6 μl/ml) and the nature of its toxicity was fungicidal. However, EO showed strong antioxidant activity with an IC(50) value at 5.6 μl/ml. Moreover, EO was found to have negligible mammalian toxicity as its LD(50) value, determined through oral administration on mice, was calculated to be 6124μl/kg body weight during safety profile assessment. During in vivo investigation on fruit systems, the Zanthoxylum EO, when tested as fumigant, provided 66.27% and 86.33% protection respectively at 1.25 μl/ml and 2.5 μl/ml against fungi infesting Piper nigrum L. fruits demonstrating its practical efficacy as a plant based antimicrobial for post harvest application.

Safety profile assessment and efficacy of chemically characterized Cinnamomum glaucescens essential oil against storage fungi, insect, aflatoxin secretion and as antioxidant

The study explores the efficacy of Cinnamomum glaucescens essential oil (EO) as insecticidal, antifungal, antiaflatoxin and antioxidant agent so as to recommend its application as plant based preservatives for food commodities. The study reports the chemical characterization of C. glaucescens oil and its 100% insecticidal activity against insect pest Callosobruchus chinensis on 12 h exposure and 98.74% oviposition deterrency at 0.15 μl/ml. The EO significantly inhibited growth and aflatoxin production by toxigenic strain of Aspergillus flavus LHP-10 at 4.5 and 3.5 μl/ml respectively. EO also showed appreciable antioxidant activity (IC(50) value=15.1 μl/ml), non phytotoxic nature on chickpea seed germination and in vivo potential as fumigant in food system providing 71.07% protection of chickpea samples from fungal contamination and 100% antifeedant activity against the insect invasion. The EO exhibited non-mammalian toxicity showing high LD(50) (3971.34 μl/kg) during oral toxicity on mice.

Botanicals as eco friendly biorational alternatives of synthetic pesticides against Callosobruchus spp. (Coleoptera: Bruchidae)—a review

The article presents the potential of botanicals in the management of Callosobruchus spp., the primary insect pest causing deterioration to a variety of stored legume grains. Different botanical formulations have been reported time to time showing pronounced insecticidal activity, repellence to pest, oviposition deterrency, adult emergence inhibition, ovicidal, larvicidal, pupaecidal activity and feeding deterrency based on their contact toxicity and fumigation effects. Some of the botanicals have also been practically proved efficacious to protect the stored food commodities from the bruchids during storage conditions. Such botanical formulations have shown their promise in integrated management of the pest as semiochemicals by showing behaviour altering efficacy against the bruchids, thereby, reducing the induced pest resistance problem which is frequently reported with synthetic pesticides. Hence, they may be recommended in food security programmes as eco-friendly and biorational alternatives of synthetic pesticides providing integrated management of the losses of stored food commodities due to infestation of bruchids.

Efficacy of essential oils of Lippia alba (Mill.) N.E. Brown and Callistemon lanceolatus (Sm.) Sweet and their major constituents on mortality, oviposition and feeding behaviour of pulse beetle, Callosobruchus chinensis L.

BACKGROUND Pulse beetle, Callosobruchus chinensis L., is the most destructive insect pest of pulses under storage in Asia and Africa. Keeping in view the negative impacts of synthetic insecticides and the demands of botanical pesticides, the present investigation explores the repellents, antifeedants, ovicidal, larvicidal and pupaecidal activity of two plant essential oils (EOs) and their major components, geranial and 1,8-cineole, when applied as fumigants for the management of the pulse beetle. RESULTS EO of Callistemon lanceolatus (Sm.) Sweet caused 100% repellency of pulse beetle in a Y-shaped olfactometer at a dose of 150 µL, while Lippia alba (Mill.) N.E. Brown EO and 1,8-cineole showed 76 and 74.7% repellency at the same dose. At 0.1 µL mL(-1) , both the oils and 1,8-cineole provided 100% insect mortality. The EO of C. lanceolatus was recorded as the most effective fumigant, showing 96.03% oviposition deterrency and 100% antifeedant activity at 0.1 µL mL(-1) . The LD(50) of L. alba (11049.2 µL kg(-1) ) and C. lanceolatus (14 626.3 µL kg(-1) ) exhibited their favourable safety profiles when recorded on mice. CONCLUSION EOs of L. alba and C. lanceolatus exhibited significant biological activity on the mortality and reproductive behaviour of pulse beetle. Based on their high LD(50) values, the oils could be safely recommended as non-mammalian toxic fumigants in management strategies for pulse beetle.

Plant Chemicals in Post Harvest Technology for Management of Fungal, Mycotoxin and Insect Contamination of Food Commodities

Higher plants produce different bioactive secondary metabolites having potential to protect the food commodities from different pests. Many of these are thought to serve an ecological function for the plants producing them, serving to defend the plants from herbivores and pathogens. Plant products may successfully replace chemical pesticides and provide eco-chemical and biorational strategy to protect cereals, pulses and other agricultural commodities from post harvest losses by microorganisms, mycotoxins and insects. Some plant products have been formulated for large scale application as safe food additives in management of different storage pests. The articles deals with current status and future prospects of plant chemicals in post harvest technology for management of fungal, mycotoxin and insect contamination of food commodities.

Assessment of toxicity and biochemical mechanisms underlying the insecticidal activity of chemically characterized Boswellia carterii essential oil against insect pest of legume seeds

The present study was undertaken to investigate the insecticidal activity of chemically characterized Boswellia carterii essential oil (EO) and its mode of action against the pulse beetle Callosobruchus chinensis and C. maculatus. GC-MS analysis depicted α-thujene (69.16%), α-Pinene (7.20) and α-Phellandrene (6.78%) as the major components of test EO. EO exhibited absolute toxicity at 0.10μl/ml air against both C. chinensis and C. maculatus following 24h exposure. EO caused a significant reduction in oviposition and further reproductive development at LC50 doses (0.050μl/ml to 0.066μl/ml in air). Compared to control, a significant elevation in ROS level accompanied with impairment in enzymatic (SOD and CAT) and non-enzymatic (GSH/GSSH) antioxidant defense system has been observed in EO exposed insect pest. However, EO has no significant effect on in vivo AChE activity. An absolute protection of Vigna radiata seeds samples exposed to EO at LC90 doses was observed without affecting seed germination. The findings revealed that the B. carterii EO has strong insecticidal potential, hence, it could be recommended as a biorational alternative to synthetic insecticides.

In silico approaches towards the exploration of rice bran proteins-derived angiotensin-I-converting enzyme inhibitory peptides

ABSTRACT Rice bran is an important underutilized by-product of rice-processing industries, and a huge amount of bran is released during rice processing. It can be used as a prime source of bioactive peptides towards the development of functional food ingredients. The aim of the study was to evaluate the potential of rice bran proteins such as glutelin, globulin, and prolamin as a precursor of bioactive peptides using various in silico approaches (BLAST, BIOPEP, PeptideRanker, PepDraw, Pepcalc, and ToxinPred). Rice bran proteins majorly release angiotensin-I-converting enzyme (ACE) and dipeptidyl peptidase IV (DPP-IV) inhibitory peptides. Papain protease can cleave the rice bran proteins effectively compared with other proteases to release ACE-inhibitory peptides. Physicochemical studies have shown that ACE-inhibitory peptides have low molecular weight profiles. These peptides have been classified as bitter peptides with a non-toxic profile. The result of this study demonstrates the usefulness of in silico approaches and provides a theoretical basis for the development of rice bran proteins as a source of bioactive peptides. The predicted prominent ACE-inhibitory peptides could be used for the development of functional food products or nutraceuticals.