Evaluation of plant oils for suppression of crown rot disease and improvement of shelf life of banana (Musa spp. AAA subgroup,cv. Robusta)

Fourteen plant oils were evaluated to control the crown rot disease caused by Lasiodiplodia theobromae and Colletotrichum musae. Five of these, viz. Ocimum sanctum, Cymbopogan citratus, C. martinii, C. nardus and Pelargonium graveolens oils completely arrested the mycelial growth of both test pathogens at their lowest concentration compared to other oils. Besides, these plant oils have also inhibited the activity of cellulolytic and pectinolytic enzymes produced by these pathogens effectively under in vitro condition. The treatment of banana fruit var. Robusta (Cavendish‐AAA) with oils of O. sanctum, C. citratus, C. nardus and C. martinii not only reduced the crown rot severity significantly, but also increased the shelf life of banana fruits. However, under low‐temperature storage (14 °C) condition, O. sanctum oil increased the shelf life of banana fruits up to 48 days without affecting their organoleptic properties. Hence, O. sanctum oil could be used as an alternative to chemical fungicides for the management of crown rot disease.     

Combination of UV‐C Treatment and Metschnikowia pulcherrimas for Controlling Alternaria Rot in Postharvest Winter Jujube Fruit

The potential of using antagonistic yeast Metschnikowia pulcherrimas alone or in combination with ultraviolet‐C (UV‐C) treatment for controlling Alternaria rot of winter jujube, and its effects on postharvest quality of fruit was investigated. The results showed that spore germination of Alternaria alternata was significantly inhibited by each of the 3 doses (1, 5, and 10 kJ m^?2) in vitro. In vivo, UV‐C treatment (5 kJ m^?2) or antagonist yeast was capable of reducing the percentage of infected wounds and lesion diameter in artificially inoculated jujube fruits, however, in fruit treated with combination of UV‐C treatment and M. pulcherrima, the percentage of infected wounds and lesion diameter was only 16.0% and 0.60 cm, respectively. The decay incidence on winter jujube fruits treated with the combination of UV‐C treatment and M. pulcherrima was 23% after storage at 0 ± 1 °C for 45 d followed by 22 °C for 7 d. None of the treatments impaired quality parameters of jujube fruit. Thus, the combination of UV‐C radiation and M. pulcherrima could be an alternative to synthetic fungicides for controlling postharvest Alternaria rot of winter jujube.     

Methyl jasmonate reduces chilling injury symptoms and enhances colour development of ‘Kent’ mangoes

Treatment of mango (Mangifera indica cv ‘Kent’) fruits with methyl jasmonate (MJ) vapour for 20 h at 20 °C reduced chilling injury (CI) symptoms and enhanced skin colour development. MJ at 10^?4 M was the most effective concentration for reducing CI and decay in fruits stored at 5 °C followed by 7 days at 20 °C (shelf‐life period). The use of 10^?5 M MJ enhanced yellow and red colour development of mangoes stored at 20 °C. These fruits possessed higher L*, a* and b* values than untreated fruits and those treated with 10^?4 M MJ. Ripening processes were inhibited by cold storage (5 °C) in control fruits. After cold storage and shelf‐life period, fruits treated with 10^?5 M MJ ripened normally and contained the highest total soluble solids (TSS). These fruits also maintained higher sugar and organic acid levels than fruits subjected to other treatments. We concluded that MJ treatment could be used to reduce decay and CI symptoms and also to improve colour development of mango fruits without adversely affecting quality. © 2001 Society of Chemical Industry     

Postharvest Changes in Antioxidant Capacity,Enzymatic Activity,and Microbial Profile of Strawberry Fruits Treated with Enzymatic and Divalent Ions

Strawberry fruits are highly perishable and cannot be stored for more than 1–2 days at ambient condition. Therefore, it was thought desirable to enhance the shelf-life of harvested strawberry using pectin methyl esterase and divalent ions. The freshly harvested fruits of strawberry were treated with different concentrations of pectin methyl esterase (50–300 units) and divalent calcium ions (calcium chloride) for 5–30 min using response surface methodology—Box–Behnken design. The treated and untreated (control) fruits were packed in plastic punnets and stored at two different temperature conditions, viz., 7 °C with 80 % relative humidity (RH) and 25 °C with 60 % RH, for evaluating the shelf-life. Appropriate physico-chemical and microbiological parameters were determined at alternate days during their storage. Overall firmness and color values (L, a, b) decreased, while physiological weight loss (percent) increased during their storage. No food-borne pathogens, viz., Salmonella, Staphylococcus, and coliforms, were observed during storage. Total antioxidant capacity and ferric reducing antioxidant power decreased, while lipoxygenase and polyphenol oxidase activities increased during storage at 7 and 25 °C. The shelf-life of treated strawberry was found to be 10 days at 7 °C as against 6 days for control fruits under similar conditions. The treated strawberry had shelf-life of 2 days compared to 1 day for control maintained at 25 °C.     

Antimicrobial effects of a bioactive glycolipid on spore-forming spoilage bacteria in milk

The growth of psychrotolerant aerobic spore-forming bacteria during refrigerated storage often results in the spoilage of fluid milk, leading to off-flavors and curdling. Because of their low toxicity, biodegradability, selectivity, and antimicrobial activity over a range of conditions, glycolipids are a novel and promising intervention to control undesirable microbes. The objective of this study was to determine the efficacy of a commercial glycolipid product to inhibit spore germination, spore outgrowth, and the growth of vegetative cells of Paenibacillus odorifer, Bacillus weihenstephanensis, and Viridibacillus arenosi, which are the predominant spore-forming spoilage bacteria in milk. For spore germination and outgrowth assays, varying concentrations (25–400 mg/L) of the glycolipid product were added to commercial UHT whole and skim milk inoculated with ～4 log₁₀ spores/mL of each bacteria and incubated at 30°C for 5 d. Inhibition of spore germination in inoculated UHT whole milk was only observed for V. arenosi, and only when glycolipid was added at 400 mg/L. However, concentrations of 400 and 200 mg/L markedly inhibited the outgrowth of vegetative cells from spores of P. odorifer and B. weihenstephanensis, respectively. No inhibition of spore germination or outgrowth was observed in inoculated UHT skim milk for any strain at the concentrations tested (25 and 50 mg/L). The effect of glycolipid addition on vegetative cell growth in UHT whole and skim milk when inoculated with ～4 log₁₀ cfu/mL of each bacteria was also determined over 21 d of storage at 7°C. Glycolipid addition at 50 mg/L was bactericidal against P. odorifer and B. weihenstephanensis in inoculated UHT skim milk through 21 d of storage, whereas 100 mg/L was needed for similar control of V. arenosi. Concentrations of 100 and 200 mg/L inhibited the growth of vegetative cells of B. weihenstephanensis and P. odorifer, respectively, in inoculated UHT whole milk, whereas 200 mg/L was also bactericidal to B. weihenstephanensis. Additional studies are necessary to identify effective concentrations for the inhibition of Viridibacillus spp. growth in whole milk beyond 7 d. Findings from this study demonstrate that natural glycolipids have the potential to inhibit the growth of dairy-spoilage bacteria and extend the shelf life of milk.     

Chemotaxonomical analysis of the essential oil aroma compounds of four different<Emphasis Type="Italic"> Ocimum</Emphasis> species from southern India

The essential oil aroma compounds of four different Ocimum species ( O. americanum, O. basilicum, O. gratissimum and O. sanctum) from southern India were analysed by solid phase microextraction (SPME)/gas chromatography (GC)/flame ionization detection (FID), SPME/GC/mass spectrometry (MS) and olfactoric evaluations. The essential oil of the whole plant of O. americanum is rich in ( E)-methyl cinnamate (72.05%), ( Z)-methyl cinnamate (9.11%), camphor (5.95%) and ß-selinene (3.43%); the essential leaf oil of O. basilicum contains ( E)-methyl cinnamate (34.49%), linalool (28.44%), camphor (13.08%), ( Z)-methyl cinnamate (6.90%) and geraniol (3.84%), whereas the essential leaf oil of O. gratissimum comprises eugenol (63.36%), ( Z)-ß-ocimene (9.11%), germacrene D (8.84%) and ß-caryophyllene (3.89%). Finally, the essential leaf oil of O. sanctum shows methyl eugenol (56.18%), ß-caryophyllene (16.60%) and germacrene D (5.10%) as main constituents. Therefore, the following chemotypes can be attributed to the analysed Ocimum samples: O. americanum, methyl cinnamate-type; O. basilicum, methyl cinnamate/linalool-type; O. gratissimum, eugenol-type; and O. sanctum, methyl eugenol-type. The character impact compounds of the essential oils of the four investigated Ocimum samples, as well as a discussion of their possible use in food products, is also given.     

Efficacy of Propolis and Cinnamon Oil Coating in Controlling Post-Harvest Anthracnose and Quality of Chilli (Capsicum annuum L.) during Cold Storage

Brazilian green propolis extract (PP) and cinnamon oil (CM) as edible coatings can be used to maximize chilli shelf life due to their antifungal properties. Antifungal effects and quality control of 5 % PP, 0.1 % CM and the combination of PP and CM incorporated with 5 % gum arabic (GA) as base coating were investigated in vitro as well as in vivo. Coated chillies were stored in cold storage of 13?±?2 °C (80–90 % relative humidity (RH)) for 28 days and 5 days at simulated marketing conditions (25?±?2 °C, 60–70 % RH). Study revealed that PP and CM alone had fungicidal effect against Colletotrichum capsici, causal organisms of chilli anthracnose. However, combined treatment of PP and CM showed the most promising results against C. capsici with 100 % inhibition on mycelia growth and spore germination. In vivo studies revealed that combined treatment of PP and CM showed a significantly (p?<?0.05) lower disease incidence (14 %) and severity score (1.5) after 33 days of storage, as well as a significant delay in the changes of weight loss, firmness, peel colour and soluble solids concentration compared with other treatments. It could be concluded that 5 % PP combined with 0.1 % CM incorporated with 5 % base coating of GA is an effective bio-fungicide for postharvest anthracnose control and retaining the quality of chilli.     

Effect of Gaseous Ozone on Papaya Anthracnose

Anthracnose caused by the fungus Colletotrichum gloeosporioides is considered as one of the most devastating postharvest disease of papaya. The aim of this study was to evaluate the effectiveness of gaseous ozone as a potential antifungal preservation technique to overcome anthracnose disease of papaya during cold storage. Different concentrations of ozone (0 (control), 0.04, 1.6, and 4 ppm) were applied for various exposure durations (48, 96, and 144 h). Radial mycelia growth and conidial germination were evaluated in vitro after fungal exposure to the different levels and durations of ozone. Significant inhibition in radial mycelia growth of C. gloeosporioides was observed (p?<?0.05) in all ozone treatments as compared to the control during 8 days of incubation at room temperature (25?±?3 °C). Ozone treatment of papaya fruit with 1.6-ppm ozone for 96 h delayed and simultaneously decreased the disease incidence to 40 % whereas disease severity was rated at 1.7, following 28 days of storage at 12?±?1 °C and 80 % relative humidity. The scanning electron microscopy showed that 4-ppm ozone caused disintegration of spore structure and did not affect the cuticular surface of fruit. Thus, ozone fumigation can reduce postharvest losses of papaya caused by anthracnose.     

Assessment of coating tomato fruit with shrimp shell chitosan and N,O-carboxymethyl chitosan on postharvest preservation

The effect of coating tomato fruit (Lycopersicon esculentum) with shrimp shell chitosan, a deacetylated form of chitin, and a chitosan derivative, i.e. N,O-carboxymethyl chitosan (NOCC) on postharvest preservation was studied. The effects of various chitosan and NOCC concentrations on fruit ripening behavior, as well as fruit physical and chemical characteristics were evaluated during storage at room temperature (25–30 °C). Coating the fruit with 2 % (w/v) chitosan or NOCC solutions was found to be more effective in extended its storage life than coating with 0.5 % (w/v) solutions. Covered tomatoes were firmer, higher in titratable acidity, and exhibited less red pigmentation than the control uncoated fruits at the end of storage. These results suggest the suitability of chitosan and its derivative NOCC as an alternative means of preserving fresh fruits.     

Study of seed morphology and influence of ageing and storage conditions on germination and seedling vigour of non-Basmati aromatic rice

The seed quality of diverse aromatic rice landraces is of great importance in tropical and sub-tropical humid environment. The changes in seed behaviour under different storage methods and durations need to be studied to conserve the seeds in better way for sowing viable and healthy seeds toward greater rice production with premium quality. Three experiments were conducted (1) to find out distinguishable seed morphological traits and (2) to understand the effects of storage duration, container and environment on germination and seedling vigour of non-Basmati aromatic rice during 6-month period (December to June) before next growing season. Among 16 aromatic rice cultivars, genetic variations in seed length (4.8–7.5 mm), seed width (2.1–3.2 mm), test weight (10.0–15.6 g), lemma and palea colour (golden-yellow, straw-yellow, black, brownish-red, purple spot at tip on straw background) were noted. Germination rate was steadily increased up to 4 months of post-harvest storage (93.0%, CV 4.9%) and attained a plateau for next 2 months. Four landraces viz. Gandheswari, Kalonunia, Kaminibhog and Radhunipagal remained dormant up to 2 months; while Mohanbhog, Gandhamalati, Gopalbhog and Badshabhog had better germinability throughout normal storage period. Among four containers, jute-made gunny bag and earthen pot were found suitable for higher germination rate (82.7–85.0%) as well as to produce better seedlings of Radhunipagal rice stored for 6 months compared to non-biodegradable material made containers (galvanized iron bin and polypropylene bag). Besides, the use of neem leaf could favour germination speed (39.5 vs 36.1%) and seedling vigour of Radhunipagal rice than no neem leaf treatment. Storage at low temperature (8±2 °C) for 6 months appeared better for greater seedling length (20.8 vs 19.3 cm) and vigour index (1897 vs 1733) of Lal Badshabhog rice compared to ambient condition (28±4 °C).     

Impact of cinnamon oil-enrichment on microbial spoilage of fresh produce

Cinnamon (Cinnamomum zeylanicum L.) oil (ranging between 25 and 500 ppm) was tested for antifungal activity against Colletotrichum coccodes, Botrytis cinerea, Cladosporium herbarum, Rhizopus stolonifer and Aspergillus niger in vitro. Oil-enrichment resulted in significant (P < 0.05) reduction on subsequent colony development for the examined pathogens. Fungal spore production inhibited up to 63% at 25 ppm of cinnamon oil concentration when compared with equivalent plates stored in ambient air. In the highest oil concentration (500 ppm) employed, fungal sporulation (except for B. cinerea) was completely retarded. In vitro, cinnamon oil reduced spore germination and germ tube length in C. coccodes, B. cinerea, C. herbarum and R. stolonifer with the effects were dependent on oil concentration. However, cinnamon oil (up to 100 ppm) accelerated spore germination for A. niger. Wound-inoculated pepper fruit accelerated B. cinerea and C. coccodes development following 3 days vapour exposure to cinnamon, and this effect was not persisted for longer exposure but no differences observed for tomato fruit. Pre-exposing tomato fruit to 500 ppm cinnamon vapours for 3 days, and then inoculated with fungi, reduced B. cinerea and C. coccodes lesion development. At the present, trials is currently focussing on the mechanisms underlying the impacts of essential oil volatiles on disease development with a major contribution to limiting the spread of the pathogen by lowering the spore load in the storage/transit atmospheres as well as the use of essential oil as an alternative food preservative.Industrial relevanceThe data presented in this work suggest that the use of pure cinnamon essential oil is an innovative and useful tool as alternative to the use of synthetic fungicides or other sanitation techniques in storage/packaging. Oil enrichment may reduce disease development with a major contribution to limiting the spread of the pathogen by lowering the spore load (spore production) in the storage/transit atmospheres as well as the use of essential oil as an alternative food preservative. The effectiveness (oil concentration) of the oil depends on the target pathogen. The effects of natural compounds on individual microorganisms (fungi and bacteria), both responsible for spoilage and food-borne pathogens, as well as the minimum concentration to gain effectiveness without affecting fresh produce quality and storage deserve further research.     

Ultrasensitive Determination of Cadmium in Rice by Flow Injection Chemiluminescence Analysis

Based on the enhancing effect of Cd²⁺ on luminol–Co²⁺ chemiluminescence (CL) system, a sensitive method for determining picogram Cd²⁺ in rice by flow injection (FI)–CL was proposed. It was found that the CL intensity increments were proportional to the concentrations of Cd²⁺, giving a calibration graph linear over the Cd²⁺ concentrations ranging from 7.0 to 5,000.0 pmol L^?1, with a detection limit of 2.0 pmol L^?1 (3σ) and relative standard deviations (RSDs) of 3.2, 2.8, and 2.5 % for 30.0, 300.0, and 1,000.0 pmol L^?1 Cd²⁺ (n?=?5), respectively. At a flow rate of 2.0 mL min^?1, a complete determination of Cd²⁺ including sampling and washing could be accomplished within 36 s, giving a sample throughput of 100 h^?1. The contents of Cd²⁺ in rice were found to be 0.07–0.10 mg kg^?1. The proposed method was also applied to the determination of Cd²⁺ in spiked human serum samples with recoveries from 95.9 to 106.3 % and RSDs less than 4.0 %.     

Similar Reduction of Salmonella enterica Typhimurium on Grape Tomatoes and Its Cross-Contamination in Wash Water by Washing with Natural Antimicrobials as Compared with Chlorine Treatment

Thymol (THY), a generally recognized as safe (GRAS) compound found in thyme oil, has inhibitory effects against foodborne pathogens including Salmonella. Hydrogen peroxide (H₂O₂) is another GRAS agent to effectively inactivate Salmonella. The aim of the current study was to develop a GRAS wash solution containing THY (or H₂O₂) and other GRAS antimicrobials (organic acids and food surfactants) that would effectively reduce Salmonella enterica on grape tomatoes and minimize cross-contamination in washing water. A systematic approach including minimum inhibitory concentration and minimum bactericidal concentration tests, inhibition zone tests, and small-scale and scaled-up tomato washing tests was used to develop such wash solutions. Grape tomatoes surface-inoculated with S. enterica Typhimurium were washed with selected solutions containing combination of 0.2 mg/ml THY, 5 % sodium dodecyl sulfate (SDS) and 2 mg/ml acetic acid (AA), 800 ppm H₂O₂, combination of 200 ppm H₂O₂ with 4 % SDS, or 200 ppm chlorine for 2 min. THY 0.2 mg/ml + SDS 5 % + AA 2 mg/ml, 800 ppm H₂O₂, or 200 ppm chlorine achieved around 7.5 log reductions of Salmonella on the tomatoes as compared to the control in tests involving 10 or 100 g tomatoes. More than 5.0 log reductions in the spent washing solutions (0.2 mg/ml THY + SDS 5 %?+?2 mg/ml AA; 800 ppm H₂O₂) was observed. None of these antimicrobial washes changed the color, pH, texture, sensory quality of the tomatoes during 16-day storage at 4 and 22 °C. These treatments also achieved a 1.3 log reduction of total aerobic bacteria. Thus, washing with 0.2 mg/ml THY + SDS 5 %?+?2 mg/ml AA and 800 ppm H₂O₂ as alternative to chlorine-based washing could be an effective method to inactivate Salmonella on tomatoes and reduce the transmission of pathogens from tomatoes to washing solutions.     

Influence of Rice Bran Wax Coating on the Physicochemical Properties and Pectin Nanostructure of Cherry Tomatoes

The effects of rice bran wax coating on the physicochemical properties such as firmness, weight loss, titratable acidity (TA) and soluble solid content (SSC) of cherry tomatoes were studied during cold storage. The chemical and nanostructure properties of chelate-soluble pectin (CSP) were also investigated by high-performance liquid chromatography (HPLC), Fourier transform infrared spectroscopy (FTIR) and atomic force microscopy (AFM). The results indicated that there was no significant difference of firmness between control (2.48 N) and waxed (2.87 N) fruits at the end of storage (20 days), while the weight loss of waxed fruits (13.54%) was lower than that of control fruits (16.02%). And the degree of esterification (DE) of both fruits decreased after cold storage by FTIR. The structural analysis by atomic force microscopy (AFM) indicated that rice bran wax coating inhibited the degradation of CSP. The CSP molecular widths ranged from 15 to 250 nm, and the vertical heights varied from 0.2 to 2.0 nm. Greater frequency (F _q ) of large width and length CSP was found in waxed fruits than in control fruits. The results suggest that rice bran wax coating was an effective way to preserve fresh fruits.     

Shelf life extension of peeled oranges by citric acid treatment

The microbial spoilage of peeled oranges was caused predominantly by Gram negative bacteriaEnterobacter agglomerans, andPseudomonasspp., and yeastsCryptococcus albidus, Rhodotorula glutinis, andSaccharomyces cerevisiae. Infusion of fruits with citric acid solution (0.1, 0.25, 0.5, and 1.0% w/v) during the peeling process reduced the surface pH of peeled fruits (from 6.0 to <4.6) and extended their shelf life in comparison with fruits infused with water only. Regardless of treatment method (dipping or infusion), maximal shelf life extension was attained with 0.5% w/v citric acid for 4°C storage or 1.0% w/v citric acid for 8 and 21°C storage. Infusion of 0.5% w/v citric acid extended shelf life of both peeled whole and chunked fruits. The extension of shelf life resulted primarily from the inhibition of spoilage bacteria.     

Fungal and termite resistance of wood treated with 4-methoxytrityl tetrafluoroborate

This study evaluates the decay and termite resistance of Scots pine (Pinus sylvestris L.) treated with 4-methoxytrityl tetrafluoroborate (MTFB). Decay resistance tests of unleached samples showed that 2%, 1.5% and 1% concentrations of MTFB (15.4 kg/m³, 11.1 kg/m³, and 7.4 kg/m³, retention levels, respectively) gave less than 2% decay of Postia placenta and concentrations of 2% and 1.5% less than 2% decay of Coniophora puteana. Wood specimens treated with 4-methoxytrityl tetrafluoroborate solutions were not protected against the brown rot fungi after a 14-day severe leaching process, suggesting excessive leaching of the chemical from wood. Treatment with 2% concentration protected against subterranean termites, Coptotermes formosanus Shiraki based on mass losses in both leached and unleached wood specimens in comparison with lower concentration levels. These results suggest that 4-methoxytrityl tetrafluoroborate might be promising to protect wood being used outdoors against termite attack. However, 4-methoxytrityl tetrafluoroborate did not protect wood against fungal decay. Field tests are needed to observe the performance of 4-methoxytrityl tetrafluoroborate treated wood in ground contact.     

Antifungal activity of lemongrass (Cympopogon citratus L.) essential oil against key postharvest pathogens

Lemongrass (Cympopogon citratus L.) oil (ranging between 25 and 500 ppm) was tested for antifungal activity against Colletotrichum coccodes, Botrytis cinerea, Cladosporium herbarum, Rhizopus stolonifer and Aspergillus niger in vitro. Oil-enrichment resulted in significant (P < 0.05) reduction on subsequent colony development for the examined pathogens. Fungal spore production inhibited up to 70% at 25 ppm of lemongrass oil concentration when compared with equivalent plates stored in ambient air. In the highest oil concentration (500 ppm) employed, fungal sporulation was completely retarded. Lemongrass oil reduced spore germination and germ tube length in C. coccodes, B. cinerea, C. herbarum and R. stolonifer with the effects dependent on oil concentration. However, lemongrass oil (up to 100 ppm) accelerated spore germination for A. niger. Work is currently focussing on the mechanisms underlying the impacts of essential oil volatiles on disease development with a major contribution to limiting the spread of the pathogen by lowering the spore load in the storage/transit atmospheres as well as the use of essential oil as an alternative food preservative.Industrial relevanceThe present study suggests that the use of pure lemongrass essential oil is an innovative and useful tool as alternative to the use of synthetic fungicides or other sanitation techniques in storage/packaging. Oil enrichment may reduce disease development with a major contribution to limiting the spread of the pathogen by lowering the spore load (spore production) in the storage/transit atmospheres as well as the use of essential oil as an alternative food preservative. The effectiveness (oil concentration) of the oil depends on the target pathogen. The effects of natural compounds on individual microorganisms (fungi and bacteria), both responsible for spoilage and food-borne pathogens, as well as the minimum concentration to gain effectiveness without affecting fresh produce quality and storage deserve further research.     

Enhanced fungal resistance of Scots pine (<Emphasis Type="Italic">Pinus sylvestris</Emphasis> L.) sapwood by treatment with methyltrimethoxysilane and benzalkoniumchloride

This paper presents possibilities for increasing the decay and mould resistance of Scots pine (Pinus sylvestris L.) sapwood by treatment: (1) in one step with mixtures of aqueous solutions of methyltrimethoxysilane (0, 5, 10, 20 or 30 % MTMS) and benzalkoniumchloride (0, 0.5, 1, 2 or 3 % BAC), and (2) in two steps, first with BAC and then with MTMS. Prior to fungal resistance tests, the treated and reference specimens were not or were subjected to artificial ageing in distilled water and in Xenotest, respectively. Insufficient anti-decay efficiency of MTMS against the brown-rot fungus Coniophora puteana and the white-rot fungus Trametes versicolor was improved in the presence of BAC, usually more apparent if this fungicide was used first and in higher concentrations. After both artificial ageing modes, the decay resistance of treated pine specimens decreased approximately 1.2–1.8 times. The none anti-mould efficiency of MTMS improved in the presence of BAC—significantly against the mould Penicillium brevicompactum but only minimally against the mould Aspergillus niger.     

Characterization and transformation of the <Emphasis Type="Italic">Opuntia ficus indica</Emphasis> fruits

Opuntia ficus indica fruits have been associated with health effects, due to their protective actions against oxidation. Nevertheless, few studies about processing of Opuntia fruits are available’; therefore, we studied the pulp characteristics and processing of a local variety, for producing beverage nectars. The pulp had an average pH of 5.64, 13.47 °Brix, with total sugars (106 g L^?1), K (1180 mg L^?1), 503.3 µg L^?1 of β carotene, 120 mg L^?1 of total phenolic compounds, 4.9 mg and 46.9 mg L^?1 respectively for betacyanins and betaxanthins and 243.4 mg L^?1 of vitamin C. The formulated nectars with 35% of pulp (N35) and 45% of pulp (N45) had respectively 14 and 15 °Brix. Minor components represent 1109 and 1112 mg L^?1 of K for N35 and N45 respectively, β carotene (318.6 µg and 362.8 µg L^?1), and vitamin C 227 and 231 mg L^?1. We confirmed the stability and acceptability of these beverages after a month of storage, after stability and panel tests. Therefore, we suggest that the pulp processing can be used as a new form of agro industrial utilization of this underutilized fruit.     

Difference between chitosan and oligochitosan in growth of Monilinia fructicola and control of brown rot in peach fruit

Chitosan (CS) and oligochitosan (OCS), as natural antifungal agents, have been primarily used as alternatives to synthetic chemical fungicides to control postharvest diseases of fruits. The effectiveness of these two agents on the growth of Monilinia fructicola to control brown rot has not yet been reported. Both spore germination and mycelial growth of M. fructicola were strongly inhibited by CS and OCS treatments in this study. Moreover, the inhibitory effect of both agents was more obvious on mycelial growth than on spore germination. By comparison of the half maximal inhibitory concentration (IC₅₀) of each, OCS treatment conferred a little better inhibitory effect on fungal growth in vitro, but the effectiveness of both treatments on brown rot control in peach fruit stored at 25 °C was very similar. The integrity of the plasma membrane of CS- or OCS-treated spores was obviously lower than that of the control. Cytoplasm leakage was significantly higher in chitosan-treated mycelia than that of the control. These results suggest that both chitosan and oligochitosan used in this study are promising natural fungicides for control of brown rot of peach.