Montinee Teerarak

Evaluation of allelopathic, decomposition and cytogenetic activities of Jasminum officinale L. f. var. grandiflorum (L.) Kob. on bioassay plants.

Methanolic extracts prepared from dried leaves of Jasminum officinale f. var. grandiflorum (L.) Kob. (Spanish jasmine) inhibited seed germination and stunted both root and shoot length of the weeds Echinochloa crus-galli (L.) Beauv. and Phaseolus lathyroides L. The main active compound was isolated and determined by spectral data as a secoiridoid glucoside named oleuropein. In addition, a decrease in allelopathic efficacy appeared as the decomposition periods increased. The mitotic index in treated onion root tips decreased with increasing concentrations of the extracts and longer periods of treatment. Likewise, the mitotic phase index was altered in onion incubated with crude extract. Furthermore, crude extract produced mitotic abnormalities resulting from its action on chromatin organization and mitotic spindle.

Physiological and cellular mechanisms of natural herbicide resource from Aglaia odorata Lour. on bioassay plants

A bioassay-guided fractionation of the allelochemicals of the ethyl acetate fraction extracted from Aglaia odorata led to isolation of a bisamide, odorine. The growth inhibitory effects of odorine and ethyl acetate fraction were studied for comparison on Echinochloa crus-galli. Odorine and ethyl acetate fraction of A. odorata could inhibit the germination and seedling growth of E. crus-galli, with ethyl acetate fraction being more potent. Thus, ethyl acetate fraction was selected for further experiment, E. crus-galli seeds were studied the effects of the ethyl acetate fraction from A. odorata leaves in wettable powder formulation on imbibition and α-amylase activity. It was found that treated seeds showed lower imbibition and α-amylase activity. The results of cytogenetic bioassay in Allium cepa roots showed that ethyl acetate fraction inhibited cell mitosis and induced mitotic abnormalities resulting from its action on chromatin organization and mitotic spindle in the exposed roots.

Allelopathic activities of Jasminum officinale f. var. grandiflorum (Linn.) Kob.: Inhibition effects on germination, seed imbibition, and α-amylase activity induction of Echinochloa crus-galli (L.) Beauv.

A methanolic extract in wettable powder from the leaves of Jasminum officinale f. var. grandiflorum (Linn.) Kob. (JWP) was inhibitory to germination and seedling growth of Echinochloa crus-galli (L.) Beauv. weeds. The inhibition percentages on E. crus-galli seed germination treated with 500 to 8,000 ppm for 7 days was about 0 to 70%, respectively, whereas shoot length was inhibited from 19.04 to 71.82% and root length was 76.31 to 100% inhibition, respectively. The imbibition and α-amylase activities in the treated E. crus-galli seeds were progressively depressed with increasing JWP concentrations. The obtained results suggest that JWP inhibited imbibition and α-amylase activity in E. crus-galli seeds during germination. Keywords: Allelopathy, α-amylase, Echinochloa crus-galli, Jasminum officinale, seed imbibition

Baby corn fermented vinegar and its vapour control postharvest decay in strawberries

Infection by Botrytis cinerea is a major cause of postharvest decay in strawberries. The efficacy of baby corn fermented vinegar (BFV) for growth inhibition of B. cinerea was investigated by diffusing 0%–0.225% acetic acid from BFV or glacial acetic acid into potato dextrose agar. BFV containing 0.225% acetic acid completely inhibited the growth of B. cinerea. Strawberry-flavoured baby corn fermented vinegar (SF-BFV) was developed to mask unfavourable smells caused by BFV. The effectiveness of BFV liquid and vapour for controlling postharvest decay in strawberries was evaluated along with associated sensory analyses. Taste panellists readily accepted fruit that had been sprayed with SF-BFV or exposed to BFV vapour, both treatments that significantly reduced fruit decay. Strawberries inoculated with B. cinerea were also tested. Shelf life at 4 °C of strawberries sprayed with SF-BFV was extended to 7 days while that of fruit exposed to BFV vapour was extended to 11 days.

Potential antioxidant and lipid peroxidation inhibition of Phyllanthus acidus leaf extract in minced pork

Objective This study investigated the effect of extraction solvents on antioxidant bio-active compounds as well as potential antioxidant and lipid peroxidation inhibition of Phyllanthus acidus (P. acidus) leaf extract in minced pork. Methods The effect of various solvent systems of water, 25%, 50%, 75% (v/v) ethanol in water and absolute ethanol on the extraction crude yield, total phenolic content, total flavonoid content and in vitro antioxidant activities of P. acidus leaves was determined. In addition, antioxidant activities of the addition of crude extract from P. aciuds leaves at 2.5 and 5 g/kg in minced pork on 2,2-diphenyl-1-picrylhydrazyl (DPPH) radical scavenging, 2,2′-Azino-bis(3-ethylbenzothiazoline-6-sulfonic acid) diammonium salt (ABTS) radical cation decolorization, reducing power and inhibition of lipid peroxidation (thiobarbituric acid reactive substances; TBARS) were determined. Moreover, sensory evaluation of the samples was undertaken by using a 7-point hedonic scale. Results The results showed that the highest crude yield (2.8 g/100 g dry weight) was obtained from water which also had the highest recovery yield for total phenolic content, total flavonoid content and the strongest antioxidant activity. The addition of crude water extract from P. acidus leaves was more effective in retarding lipid peroxidation and higher antioxidant activity than control and butylated hydroxytoluene in minced pork. In particular, the samples containing P. acidus extract had no significant effect on the sensory scores of overall appearance, color, odor, texture, flavor, and overall acceptability compared to the control. Conclusion Water solvent was an optimally appropriate solvent for P. acidus leaf extraction because of its ability to yield the highest amount of bio-active compounds and in vitro antioxidant property. Particularly, P. acidus crude water extract also strongly expressed the capacity to retard lipid oxidation, radical scavenging, radical cation decolorization and reducing power in minced pork. The results of this study indicated that P. acidus leaf extract could be used as natural antioxidant in the pork industry.

Susceptibility of Klebsiella pneumoniae on coriander leaves to liquid- and vapor-phase ethanol

The bio-control of ethanol on Klebsiella pneumoniae on fresh coriander leaves for significantly reducing consumer health risk was investigated. Washed and sterilized leaves of coriander were inoculated with K. pneumoniae cultured in Trypticase Soy broth. Susceptibility of the K. pneumoniae to liquid- and evaporated vapor-phase ethanol (EVE) was then examined in vitro Complete inhibition of K. pneumoniae was found with 18% (v/v) liquid ethanol. Exposure for 15 min to EVE (9.00 ± 0.8 mmol L(-1)) completely destroyed K. pneumoniae (4.04 ± 0.02 log CFU/ml) spread on Mueller Hilton agar at 30 ± 2°C. The effect of EVE with and without evaporated water vapor (EWV) on the susceptibility of K. pneumoniae on fresh coriander leaves was examined. While exposure to EVE affected the survival of K. pneumoniae, the degree of reduction depended on both the inoculation level and the EWV. Complete reduction of K. pneumoniae was achieved for the low inoculation level by EVE alone (37 ± 2% relative humidity; RH) but susceptibility was reduced with EWV (high RH; 80 ± 2%). Scanning electron microscope (SEM) images of inoculated coriander leaves confirm the effects of EVE in reducing levels of K. pneumoniae Exposure to EVE alone proved an effective bio-control for K. pneumoniae on fresh coriander leaves.

Antioxidant activities and heat stability of edible flowers of Telosma minor and Sesbania javanica

ABSTRACT Aqueous and ethanolic extracts from the edible flowers of Telosma minor (cowslip creeper), and Sesbania javanica (sesbania) were assessed for their their total phenolics, 1,1-diphenyl-2-picrylhydrazyl (DPPH) radical-scavenging activity, and anti-lipid peroxidation ability. Aqueous extracts of cowslip creeper had the highest activities as a DPPH radical scavenger and as an inhibitor of lipid peroxidation. The value of the half-maximal effective concentration (EC50) for DPPH radical-scavenging of the aqueous cowslip creeper extract was 252.5 mg L−1, compared to the EC50 values for the standards, ascorbic acid, and butylated hydroxytoluene (BHT), which were 2.26 and 21.80 mg L−1, respectively. For anti-lipid peroxidation, the IC50 (the half-maximal inhibition concentration) value of the aqueous cowslip creeper extract was 1539.93 mg L−1 while the IC50 value of BHT was 683.5 mg L−1. The aqueous extract of cowslip creeper had the highest total phenolic concentration (991.3 mg gallic acid equivalents 100 g−1 DW). The total phenolic content in cowslip creeper and sesbania flowers had high positive correlation with their antioxidant activities and anti-lipid peroxidation. The aqueous extract of sesbania flowers was the most heat stable antioxidant (100°C for 15 or 30 min), decreasing in total phenolic content but no changes in DPPH scavenging or in anti-lipid peroxidation activity.

Retarding Changes of Postharvest Qualities of Sweet Basil (Ocimum basilicum Linn.) by Vapor-Phase Vinegar

ABSTRACT Fresh leaves of sweet basil (Ocimum basilicum) were exposed to ambient upland rice vinegar (URV) vapor containing 4% acetic acid (AA) for 0, 2, 4, 6, 8, or 10 min, before packing in polyethylene bags and storing at 12°C. This extended the postharvest storage life of sweet basil by retaining greenness, freshness, and antioxidants. The gas chromatography-mass spectrometry (GC-MS) results showed a number of other volatiles in URV vapor, including ethyl acetate, propane, pentanal, and acetic acid.