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The article discusses a study which analyzed the physicochemical parameters, sensory attributes, and total aroma emission of Fuji apples in relation to storage conditions, storage duration, and shelf life period. In this study, commercially ripe fruit were analyzed after 3, 5, and 7 months of cold storage in normal atmosphere or under 3 different controlled atmosphere (CA) treatments, after which apples were kept at 20 °C for 1, 5, and 10 days.

This work determined the effects of harvest date and storage conditions on fruit quality and aroma production in 'Fuji' apples over two years. Fruits were harvested on two dates and stored in different atmospheres: AIR (21% O[sub 2] + 0.03% CO[sub 2]); SCA (3% O[sub 2]+2% CO[sub 2]); ULO1 (1% O[sub 2] + 1% CO[sub 2]) and ULO2 (1% O[sub 2]+2% CO[sub 2]). After 3, 5 and 7 months of storage (plus 1, 5 and 10 days at 20°C) fruit firmness, titratable acidity, soluble solids, skin colour, physiological disorders and aroma production were measured. 'Fuji' apple quality was maintained during the harvest and storage periods, however fruit quality was better in controlled than AIR atmospheres. ULO1 was more effective in maintaining firmness during storage than other treatments, especially in earlier-harvested apples. Differences in soluble solids and titratable acidity were not always significant. The incidence of physiological disorders was low. Maximum aroma production was reached in fruits stored in AIR atmosphere (after 5 days at 20°C) for early-harvested fruits in 2000/2001 season. In general, aroma levels decreased over time in different storage treatments. Fruits stored in ultra low oxygen atmospheres showed low aroma production, especially after long storage periods (7 months) in ULO2 atmosphere. ULO1 (1% O[sub 2] + 1% CO[sub 2]) was a good atmosphere for maintaining quality and aroma production in 'Fuji' apples during storage and shelf-life periods. [ABSTRACT FROM AUTHOR]

Aims: Development of a PCR assay for detection of aeromonads carrying the hly A and/or aer A genes in fish. Methods and Results: The protocol involves an overnight selective enrichment step in tryptic soy broth yeast extract containing 10 µg ml-1 of ampicillin followed by extraction of DNA and PCR amplification of two haemolysin genes that contribute to the virulence of Aer. hydrophila . This procedure can detect initial populations of 1–10 cfu g-1 within 24 h in artificially contaminated samples. In naturally contaminated fish, both genes were detected in 13 out of 14 fresh fish lots (aeromonads levels between < 1 and 5·42 log cfu g-1 ) and in 4 out of 16 lots of vacuum-packed cold-smoked fish (aeromonads levels between < 1 and 3·37 log cfu g-1 ). Before enrichment, dominant species were Aer. hydrophila HG1 (aer A+ hly A+ ), Aer . bestiarum HG2 (aer A+ hly A+ ) and Aer. caviae HG4 (aer A– hly A– ). After enrichment, Aer. hydrophila HG1 (aer A+ hly A+ ) was dominant. Conclusions: Fresh fish and even smoked fish carry hly A+ and/or aer A+ aeromonads that can be detected by PCR within 24 h. Significance and Impact of the Study: The PCR assay described offers considerable potential as a rapid method with specificity, sensitivity and simplicity. [ABSTRACT FROM AUTHOR]

Aims: To evaluate the public health significance of representative strains of two Aeromonas spp., mainly from freshwater fish, on the basis of production of virulence-associated factors and presence of the haemolytic genes aerA and hlyA. Methods and Results: Eleven strains of Aer. hydrophila, three strains of Aer. veronii biovar sobria (all from freshwater fish) and one strain of Aer. hydrophila from human diarrhoea were tested for potential virulence traits and for the presence of the haemolytic genes aerA and hlyA. Ten Aer. hydrophila isolates were aerA[sup +]hlyA[sup +] and two aerA[sup +]hlyA[sup -]. Aeromonas veronii biovar sobria isolates were aerA[sup -]hlyA[sup -]. Strains from the three genotypes showed enterotoxic activity in the suckling mouse assay. At 28°C, four Aer. hydrophila fish strains could be considered as potentially virulent (possessing at least two of these characteristics: haemolytic, cytotoxic and enterotoxic). One Aer. veronii biovar sobria strain and the clinical isolate were cytotoxic on Vero cells. When grown at 4°C, these six isolates fulfilled virulence criterion, but at 37°C, only one fish strain, an Aer. hydrophila, did. Conclusions: The potential health risk derived from the presence of Aer, hydrophila and Aer. veronii biovar sobria in ice-stored freshwater fish should not be underestimated. Significance and Impact of the Study: Expression of virulence factors is affected by temperature incubation and not always related to the presence of haemolytic genes. [ABSTRACT FROM AUTHOR]

Aims: This work was carried out to study the acid production by Lactococcus lactis subsp. lactis strains isolated from goat’s milk and goat cheese (Valdeteja variety) in order to select a suitable starter culture for industrial goat cheese manufacturing. Methods and Results: The titrable acidity of 45 Lactococcus lactis subsp. lactis strains isolated from a home-made batch of Valdeteja cheese with excellent sensory characteristics was measured over a period of 18 h. The strains were divided into two groups depending on the acid production rate: 20 fast acid producer (F) strains and 25 slow acid producer (S) strains. The kinetic parameters (lag phase, maximum acid production rate and value of upper asymptote curve) of the acid production curves for F and S strains were significantly (P < 0·001) different. Conclusions: Significant (P < 0·001) differences between titrable acidity of F and S strains were observed after the second hour of incubation. Significance and Impact of the Study: An F strain acetoin producer (Lactococcus lactis subsp. lactis 470Ch2) was selected as autochthonous starter culture for industrial Valdeteja goat cheese manufacturing. [ABSTRACT FROM AUTHOR]

Investigates the quality and aroma production of Doyenne du Comice pears. Improvement of fruit firmness; Influence of storage atmosphere on pears aroma; Measurement of the ethylene production of fruits.