Phenolic acids are components of the plant defence system; however few studies had been done with fruits. The objective of this experiment was to elucidate the changes in phenolic acid content in tomato fruits in response to pathogenic attack. Tomato fruit ÔPintoÕ was inoculated with spores of Alternaria alternata and stored for 10 days at 25°C and 90-92% of relative humidity. Sampling of epicarp and mesocarp tissues of control and infected tomato fruits were done every 2 days. Phenolic acids were extracted from each tissue and identified by HPLC coupled to a mass spectrometer. Quantification was done based in standard curves. In vitro evaluation of the phenolic acid effect either one-by-one and in a mixture of phenolic acids (MPA) over A. alternata spore germination was done with 25, 50, 100, 200 and 500 mm. It was found caffeic, chlorogenic and vanillic acids in both epicarp and mesocarp tomato tissues before the beginning of the experiment. Infected tomato fruits showed significantly higher concentrations of vanillic acid in the epicarp, only. Chlorogenic acid and the MPA inhibit spore germination by 30%, whereas caffeic acid and vanillic acid inhibit 16% at 500 mm. It was concluded that chlorogenic, vanillic and caffeic acids are phytoanticipins in tomato fruit. The concentration of vanillic acid also increases in tomato fruit epicarp as part of the defence system during a pathogenic attack.www.blackwell-synergy.com

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Benzyl isothiocyanate (BITC) is known to be a strong antifungal compound in vitro against different fungi. The effectiveness of benzyl isothiocyanate to control Alternaria alternata growth in vitro and in vivo was tested. BITC in vitro activity was evaluated in A alternata growing on potato dextrose agar and exposed to 0.025, 0.05, 0.1, 0.2 or 0.4 mg ml −1 . In vivo activity was evaluated by exposing A alternata-inoculated tomato fruits for either 18 or 36 h to 0.28 or 0.56 mg ml −1 BITC packed on low-density polyethylene film (LDPF) bags. Additionally, the effect of BITC on post-harvest physiology and tomato quality throughout storage at 20 • C was evaluated daily by monitoring respiration rate and ethylene production, whereas total soluble solids, pH, titratable acidity and fresh weight loss were measured every 3 days. Results showed that the minimal inhibitory concentration of BITC in vitro was 0.1 mg ml −1 . A combined use of 0.56 mg ml −1 BITC with LDPF for 18 h was the optimum treatment to control Alternaria rot in packed tomato fruit. No effect of BITC on respiration rate, ethylene production, total soluble solids, pH, weight loss and titratable acidity was observed. Results suggest that BITC can be used as a post-harvest treatment to control Alternaria rot in tomato fruit without detrimental effects on the tomato post-harvest quality.

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Angiotensin I-converting enzyme inhibitory (ACEI) activity was evaluated and compared in <3 KDa water-soluble extracts (WSE) isolated from milk fermented by wild and commercial starter culture Lactococcus lactis strains after 48 h of incubation. The highest ACEI activities were found in WSE from milk inoculated with wild L. lactis strains isolated from artisanal dairy products and commercial starter cultures. On the other hand, the lowest ACEI activities were found in WSE from milk inoculated with wild strains isolated from vegetables. Moreover, the IC(50) values (concentration that inhibits 50% activity) of WSE from artisanal dairy products were the lowest, indicating that these fractions were the most effective in inhibiting 50% of ACE activity. In fact, a strain isolated from artisanal cheese presented the lowest IC(50) (13 μg/mL). Thus, it appears that wild L. lactis strains isolated from artisanal dairy products and commercial starter cultures showed good potential for the production of fermented dairy products with ACEI properties.

The ability of Bacillus subtilis, strain ALICA to produce three mycolytic enzymes (chitinase, β-1,3-glucanase, and protease), was carried out by the chemical standard methods. Bacillus subtilis ALICA was screened based on their antifungal activity in dual plate assay and cell-free culture filtrate (25%) against five different phytopathogenic fungi Alternaria alternata, Macrophomina sp., Colletotrichum gloeosporioides, Botrytis cinerea, and Sclerotium rolfesii. The B. subtilis ALICA detected positive for chitinase, β-1,3-glucanase and protease enzymes. Fungal growth inhibition by both strain ALICA and its cell-free culture filtrate ranged from 51.36% to 86.3% and 38.43% to 68.6%, respectively. Moreover, hyphal morphological changes like damage, broken, swelling, distortions abnormal morphology were observed. Genes expression of protease, β-1,3-glucanase, and lipopeptides (subtilosin and subtilisin) were confirmed their presence in the supernatant of strain ALICA. Our findings indicated that strain ALICA provided a broad spectrum of antifungal activities against various phytopathogenic fungi and may be a potential effective alternative to chemical fungicides.