Influence of postharvest hot water treatment on nutritional and functional properties of kumquat (Fortunella japonica Lour. Swingle Cv. Ovale) fruit

The present study investigated the influence of a hot water dip (HWD) for 2 min at 50 degrees C, a standard and effective treatment for postharvest decay control of citrus fruit, on the nutritional and health-related properties of kumquats. The results show that most of the parameters examined, including titratable acidity, soluble solids content, maturity index, glucose, fructose, sucrose, ascorbic acid, dehydroascorbic acid, alpha- and gamma-tocopherols, beta-carotene, zeaxantin, rhoifolin, and antioxidant activity, were not significantly affected by treatment. The levels of beta-cryptoxanthin, narirutin, and total flavonoids increased after HWD, whereas lutein and total phenols decreased. The concentration of the essential oil and the relative percentage of the individual components of the essential oil were not affected by HWD except for the minor compound p-menta-1,5-dien-1-ol, which increased after HWD. After storage, lower levels of glucose, total sugars, beta-carotene, beta-cryptoxanthin and lutein were recorded in HWD fruit. A decrease in antioxidant activity and increases in alpha-tocopherol and total vitamin E were found both in control and HWD fruit. The influence of HWD at 50 degrees C for 2 min on individual nutraceuticals and health-related properties was thus generally low and may depend on storage conditions.     

A longitudinal study of sows and boars raised by smallholder farmers in the Philippines

We conducted a longitudinal study to obtain baseline information about the health and productivity of sows and boars raised by smallholder-pig raisers in the Philippines, and test constraints and opportunities to smallholder-sow production that had been identified previously in a cross-sectional study [More, S.J., Lee, J.-A.L.M., La?ada, E.B., Taveros, A.A., Cotiw-an, B.S., 1999. Weight-for-age of growing pigs raised by smallholder farmers in the Philippines. Prev. Vet. Med. 41, 151-169]. Over 12-18 months, we collected data during monthly on-farm visits about 213 sows raised in 119 herds at 2 sites and 32 boars in 31 herds at 1 site. Sow reproductive performance was low and boars were used only infrequently (an average of 0.9 services/month). Using repeated-measure analyses, we identified sow nutrition and piglet care (such as provision of creep feed and unrestricted access to the sow) as important husbandry issues associated with increased sow productivity.     

A longitudinal study of unweaned piglets raised by smallholder farmers in the Philippines

We conducted a longitudinal study to obtain detailed baseline information about the health and productivity of unweaned piglets raised by smallholder pig raisers in the Philippines, and to identify constraints and opportunities to smallholder-piglet production. At two sites in the Philippines, we collected data about 242 litters from 173 sows in 102 herds during on-farm visits over 12-18 months. Preweaning mortality at the northern and southern sites was 17 and 9%, respectively. Of the piglet deaths at the northern site, 49% occurred within 24h of birth. Pig raisers used few of the recognised interventions known to reduce neonatal piglet mortality, although >50% of litters were given iron injections at the northern site and kept in a farrowing pen with a barrier at the southern site. Creep feeding was more common at the northern site but the nutritive value of the feeds given to piglets was low. We used repeated-measures and time-to-event analyses. Our results suggest that targeted extension (addressing, in particular, management issues relating to neonatal piglets) can contribute to increased productivity of unweaned piglets.     

Hydrogen peroxide localization and antioxidant status in the recovery of apricot plants from European Stone Fruit Yellows

Hydrogen peroxide (H₂O₂) localization and roles of peroxidases, malondialdehyde and reduced glutathione were compared in leaves of apricot (Prunus armeniaca) plants asymptomatic, European Stone Fruits Yellows (ESFY)-symptomatic and recovered. Nested PCR analysis revealed that Candidatus Phytoplasma prunorum, is present in asymptomatic, symptomatic and recovered apricot trees, confirming previous observations on this species, in which recovery does not seem to be related to the disappearance of phytoplasma from the plant.H₂O₂was detected cytochemically by its reaction with cerium chloride, which produces electron-dense deposits of cerium perhydroxides. H₂O₂was present in the plasmalemma of the phloem cells of recovered apricot plant leaves, but not in the asymptomatic or symptomatic material. Furthermore, by labelling apricot leaf tissues with diaminobenzidine DAB, no differences were found in the localization of peroxidases.Protein content in asymptomatic, symptomatic and recovered leaves was not significantly different from one another. In contrast, guaiacol peroxidase activity had the following trend: symptomatic > recovered > asymptomatic, whereas reduced glutathione content followed the opposite trend: asymptomatic > recovered > symptomatic. Moreover, no differences were observed in malondialdehyde concentrations between asymptomatic, symptomatic and recovered leaves. The overall results suggest that H₂O₂ and related metabolites and enzymes appear to be involved in lessening both pathogen virulence and disease symptom expression in ESFY-infected apricot plants.     

Genetic and antigenic characterization of the surface lipoprotein P48 of Mycoplasma bovis

The presence of a membrane lipoprotein homologous to the P48 of Mycoplasma agalactiae was investigated in different Mycoplasma bovis isolates selected by geographical locations and biological properties. Its potential as a diagnostic tool was also discussed. The presence of a specific signal observed in all M. bovis field isolates probed with a rabbit antiserum raised against the M. agalactiae recombinant P48 demonstrated that this protein is structurally and antigenically conserved within the M. bovis cluster. No signal was detected when testing six different mycoplasma species found in cattle. The p48 gene was identified by PCR approach and partially sequenced. Full length gene sequence was obtained by direct bacterial chromosome sequencing. Five UGAs were selectively mutated into UGG and the full length mutated gene, lacking the signal peptide, was cloned and expressed in Escherichia coli. The purified recombinant antigen (r-P48) was evaluated as a potential marker of infection using a panel of 86 well-characterized sera from experimentally and naturally infected cattle. Specific IgM antibodies were detected within 6-9 days after experimental infection followed by an IgG response lasting from the third/fourth week after contact. Although antibody titers were well below those observed in sheep or goats infected with M. agalactiae, results suggest that M. bovis r-P48 can be used as a specific marker of infection.     

Biological and DNA evidence of two dissimilar populations of the Rhipicephalus sanguineus tick group (Acari: Ixodidae) in South America

In this work, the biology, mitochondrial DNA and fertility of hybrids from two strains of Rhipicephalus sanguineus, from Brazil and Argentina, were compared. Engorged larvae, nymphs and adults from Argentina weighed more and the engorgement period of adult females was significantly longer than those of their Brazilian counterparts, whereas adult female tick yield rate was higher for the Brazilian strain. High intraspecific divergence of mitochondrial DNA was detected between R. sanguineus from Brazil and Argentina. On the other hand, a strong genetic relationship was detected between European and Argentinean R. sanguineus populations while the Brazilian population appeared to be related to the African Rhipicephalus turanicus. Adult hybrid females laid eggs, which were mostly unviable, whereas a mean of more than 1400 larvae hatched per egg mass from pure Brazilian and Argentinean strains. These results showed that differences between these strains are greater than previously assumed and that the biosystematic status of R. sanguineus ticks from South America should be re-evaluated. Wide variations, such as these might account for the reported worldwide differences in biology and vector capacity of this species.     

Synthesis of some 3-phenyl-1-substituted(or 1,1- disubstituted)prop-2-yn-1-ols and their in-vivo activity against some phytopathogenic fungi

Thirty-two 3-phenyl-1-monosubstituted(or 1, 1-disubstituted)prop-2-yn-1-ols, mostly with heterocyclic substituents, and four derivatives, were synthesised and tested in vivo against eight fungal plant pathogens of different taxonomic classes. No compound showed a wide spectrum of activity, however, nine of them were effective against Sphaerotheca fuliginea on Cucumis sativus, both in direct protectant tests and in systemic protectant tests by root application.     

Simultaneous determination of eight water-soluble vitamins in supplemented foods by liquid chromatography

A fast, simple, and reliable method for the isolation and determination of the vitamins thiamin, riboflavin, niacin, pantothenic acid, pyridoxine, folic acid, cyanocobalamin, and ascorbic acid in food samples is proposed. The most relevant advantages of the proposed method are the simultaneous determination of the eight more common vitamins in enriched food products and a reduction of the time required for quantitative extraction, because the method consists merely of the addition of a precipitation solution and centrifugation of the sample. Furthermore, this method saves a substantial amount of reagents as compared with official methods, and minimal sample manipulation is achieved due to the few steps required. The chromatographic separation is carried out on a reverse phase C18 column, and the vitamins are detected at different wavelengths by either fluorescence or UV-visible detection. The proposed method was applied to the determination of water-soluble vitamins in supplemented milk, infant nutrition products, and milk powder certified reference material (CRM 421, BCR) with recoveries ranging from 90 to 100%.     

Residue levels and effectiveness of pyrimethanil vs imazalil when using heated postharvest dip treatments for control of Penicillium decay on citrus fruit

The influence of fungicide concentration and treatment temperature on residue levels of pyrimethanil (PYR) in comparison with the commonly used fungicide imazalil (IMZ) was investigated in orange fruits following postharvest dip treatments. The dissipation rate of PYR residues was recorded as a function of storage conditions. The fungicide efficacy against green and blue molds caused by Penicillium digitatum and Penicillium italicum, respectively, was evaluated on different citrus varieties following the fungicide application at 20 or 50 degrees C. Residue levels of PYR in Salustiana oranges were significantly correlated with the fungicide dosage, but residue concentrations were notably higher (ca. 13-19-fold) after treatment at 50 degrees C as compared to treatments at 20 degrees C. After treatment at temperatures ranging from 20 to 60 degrees C, PYR and IMZ residues in Salustiana oranges were significantly correlated with dip temperatures. Dissipation rates of PYR during storage were negligible in both Salustiana and Tarocco oranges. Results obtained on wounded, noninoculated Miho satsumas revealed that when treatments were performed at 50 degrees C, PYR or IMZ concentrations needed to achieve the complete control of decay were 8- and 16-fold less than by treatment at 20 degrees C. When fruits were inoculated with either P. digitatum or P. italicum, the application of 400 mg L(-1) PYR at 20 degrees C or 100 mg L(-1) PYR at 50 degrees C similarly reduced green and blue mold development. These results were corroborated by storage trials on Marsh grapefruits and Tarocco oranges. The lowest concentration of PYR required to achieve almost total protection of the fruit against decay accounted for 100 mg L(-1) at 50 degrees C and 400 mg L(-1) at 20 degrees C, respectively. Treatments did not affect fruit external appearance, flavor, and taste. It is concluded that postharvest PYR treatment represents an effective option to control green and blue mold in citrus fruit and that integration of fungicide applications and hot water dips may reduce the possibility of selecting fungicide-resistant populations of the pathogen, as a consequence of increased effectiveness of the treatment.