The aim of this work was to evaluate the effect of wedge and dice cut format and storage temperature on the physiological activity, firmness and organic acid and sugar content of fresh cut pears (Pyrus communis L.) 'Packham's Triumph' and 'Shinco'. The whole fruit was washed, peeled, cut, packed in modified atmosphere and subsequently stored at 5 and 8 degrees C for 8 days. In 'Packham's Triumph' the storage temperature and the cutting format separately showed a significant effect on the physiological activity, which was lower in the wedges stored at 5 degrees C. The cutting format and storage temperature, separately, also showed a significant effect on the firmness, the wedges showed a 12% higher firmness than dices (4.9 kg(-f)) while wedges and dices of 'Packham's Triumph' pears stored at 5 degrees C were firmer (5.3 kg(-f)) than those stored at 8 degrees C (5.1 kg(-f)). The interaction of the cutting format and storage temperature showed a significant effect on organic acid, the content of oxalic and malic acids was higher in wedges stored at 5 degrees C compared with the other cutting format at both storage temperatures at the end of the storage. In 'Shinco', the cutting format and the storage temperature showed a significant effect on the ethylene rate, which was lower in the wedges stored at 5 degrees C than those stored at 8 degrees C. At the end of storage, the content of malic acid was affected by the cut format which was 18% higher in dices in comparison with wedges while the fructose content in dices stored at 5 degrees C was the highest in comparison with the other cutting formats stored either at 5 or 8 degrees C. In summary, the 'Packham's Triumph' and 'Shinco' pears can be minimally processed under wedge and dice cut format, respectively, and they both must be stored at 5 degrees C packed in modified atmosphere in order to preserve their quality.

The effect of calcium propionate (PCa) 1% p/v, ethylenediaminetetraacetic acid (EDTA) 0.1% p/v, cysteine (CIS) 0.5% p/v and citric acid (AC) 0.5% p/v were evaluated on the total phenol content, antioxidant capability and respiration rate of 'Packham's Triumph' pear wedges, packed in modified atmosphere (MA, 8-11% O-2 and 14-16% CO2 after 6 days of storage) and stored at 5 degrees C for 8 days. The treatments were control (washed with water at 5 degrees C, MA), PCa + EDTA + CIS + AC (MA), and PCa + EDTA + CIS (MA). The evaluations were performed on days 1, 3 and 8 after processing. The respiration rate of the control samples was 42% lower than the pear wedges treated with PCa and anti-browning agents (10-12 mg CO2 kg(-1) h(-1)) during 8 days of storage. On days 3 and 8, the pear wedges treated with PCa + EDTA + CIS + AC and PCa + EDTA + CIS showed respiration rates 55% higher than the control samples. On the other hand, the total phenol content was preserved along the storage period, even though it was 27% lower than the content in peeled fresh fruit (265 mg 100 g(fw)(-1)). At the end of the storage period, the PCa + EDTA + CIS showed the highest phenolic content (214 mg 100 g(fw)(-1)), while it was lower in the other treatments (146 mg 100 g(fw)(-1)). According to the antioxidant capability, non-significantly statistical differences were shown throughout shelf-life, except those wedges treated with PCa + EDTA + CIS whose antioxidant capability was increased by 67%. After the minimally processing operations chemical agent immersions and MA packaging, the total phenol content was diminished compared to the initial fresh flesh fruit. In addition, MA could have a high impact on gas atmosphere inside the packages and preservation of the functional quality of 'Packham's Triumph' pear wedges because no differences were detected among treatments.

Currently in the industry of fresh salads, watercress is shown as an alternative supply of gourmet products, being recognized for its high content of health promoting compounds such as antioxidants and phenolic compounds. The aim of this study was to evaluate different sanitizing agents such as chlorine dioxide (CD, 10 mg L-1), acidified sodium chlorite (ASC, 500 mg L-1) and peroxyacetic acid (PAA 90 mg L-1) as an alternative to sodium hypochlorite (SH, 100 mg L-1). The treated samples were stored under modified atmosphere packaging (MAP) for 13 days at 5 degrees C and 95% RH. Watercress treated with SH in a perforated bag (air atmosphere conditions) was used as a control. The evolution of the psychrophilic bacteria counts, during 13 days of refrigerated storage, was determined in Plate Count Agar, and incubated at 5 degrees C for 7 days. Determinations were performed in triplicate. Sensory analyses were carried out to determine the effect of all treatments on the watercress quality. All treatments in MAP showed a gradual decrease in O-2 levels by 37% and an increase in CO2 levels by 316% on day 13, relative values on day 0. During the storage period, MAP maintained the antioxidant levels of around 2 mg g(-1) of Trolox activity, while watercress stored in perforated bags showed a decrease to 1 mg g(-1) Trolox activity on day 13. The total phenolic contents showed a similar trend as the antioxidant levels, where MAP and perforated bags reached 3 and 3.9 mg g(-1) gallic acid equivalents (GAE). Initial counts of psychrophiles in raw material reached 6.4 log CFU g(-1). However, after one day of storage all treatments reduced to counts between 1 and 2 log units. The modified atmosphere combined with all sanitizers turned out to be a useful tool to maintain bioactive compounds levels as well as extend the shelf-life of watercress stored at 5 degrees C.

Safety of fresh-cut products is largely affected by the microbial load of raw material. In this sense, a hydroponic production system allows to reduce microbial contamination, as long as the quality of the used water on the production system is ensured. This can be achieved through water sanitation. Moreover, treatments used to sanitize the nutrient solution can have an effect on its composition affecting subsequently the crop yields, especially if a strong oxidizing agent such as ozone (O3) is used. In this work the effect of periodically gaseous O3 application on nutrient solution composition and its impact on the yield of red chard baby leaves was evaluated. O3 applications were performed every two days of culture at doses of 0 (control), 0.50, 1.0 and 2.0 mg L-1 for 3 min. Three harvests were performed on days 10, 17 and 26 after transplant. Macroand micronutrients, dissolved oxygen (DO) and electrical conductivity (EC) of the nutrient solution were determined. Red chard yield was evaluated by fresh mass production and leaf area. Nutrient solution macronutrients were not affected by O3, while micronutrients such as Fe and Mn contents decreased by 88 and 40%, respectively, on 0.50 mg L-1 dose. DO reached 2.0 mg L-1 increases up to 50% more than the control in each application. EC was not significantly affected by O3 applications (ranges 2.46 and 2.82 dS m-1 at 25°C). However, all O3 treatments increased red chard yield compared to the control. The dose of 0.50 mg L-1 produced the highest fresh matter and leaf area (53 and 22% more, respectively, than the control). It is concluded that O3 applications to hydroponic red chard culture increase yield even though the availability some micronutrients as Fe and Mn could be affected.

An immunohistochemstry (IHC) method to detect scrapie in sheep third eyelid lymphoid tissue was applied in post mortem animals. This method would allow to carry out the diagnosis in Chile, including the preclinical phase of the disease in sheep flock. Eighty samples from two year old sheep were obtained. Fourty two showed neurological signs consistent with scrapie and thirty eight came from slaughterhouse. Another thirteen blind samples were provided by a Reference Center (RC) in addition to sixteen obex used as controls. Samples were evaluated in sections with hematoxilin-eosin and classified as suitable if presenting at least four lymphoid follicles in the tissue. Based on this, seventy four out of ninety samples were considered suitable. The IHC results showed that all samples were negative to scrapie and only seven provided by the RC were positive. All obex samples were positive to immunostaining by PrPsc, unlike negative controls. The results demosntrate that this diagnostic tool may be considered for monitoring the sanitary condition related to scrapie in the ovine flock in Chile.

SUMMARY An immunohistochemstry (IHC) method to detect scrapie in sheep third eyelid lymphoid tissue was applied in post mortem animals. This method would allow to carry out the diagnosis in Chile, including the preclinical phase of the disease in sheep flock. Eighty samples from two year old sheep were obtained. Fourty two showed neurological signs consistent with scrapie and thirty eight came from slaughterhouse. Another thirteen blind samples were provided by a Reference Center (RC) in addition to sixteen obex used as controls. Samples were evaluated in sections with hematoxilin-eosin and classified as suitable if presenting at least four lymphoid follicles in the tissue. Based on this, seventy four out of ninety samples were considered suitable. The IHC results showed that all samples were negative to scrapie and only seven provided by the RC were positive. All obex samples were positive to immunostaining by PrP Sc , unlike negative controls. The results demosntrate that this diagnostic tool may be considered for monitoring the sanitary condition related to scrapie in the ovine flock in Chile.

An immunohistochemstry (IHC) method to detect scrapie in sheep third eyelid lymphoid tissue was applied in post mortem animals.This method would allow to carry out the diagnosis in Chile, including the preclinical phase of the disease in sheep flock.Eighty samples from two year old sheep were obtained.Fourty two showed neurological signs consistent with scrapie and thirty eight came from slaughterhouse.Another thirteen blind samples were provided by a Reference Center (RC) in addition to sixteen obex used as controls.Samples were evaluated in sections with hematoxilin-eosin and classified as suitable if presenting at least four lymphoid follicles in the tissue.Based on this, seventy four out of ninety samples were considered suitable.The IHC results showed that all samples were negative to scrapie and only seven provided by the RC were positive.All obex samples were positive to immunostaining by PrP Sc , unlike negative controls.The results demosntrate that this diagnostic tool may be considered for monitoring the sanitary condition related to scrapie in the ovine flock in Chile.

Piscirickettsia salmonis is the aetiological agent of piscirickettsiosis, a disease which affects a variety of teleost species and that is particularly severe in salmonid fish. Bacterial-free supernatants, obtained from cultures of three isolates of Piscirickettsia salmonis, were inoculated in Atlantic salmon, Salmo salar L., and in three continuous cell lines in an effort to determine the presence of secretion of extracellular products (ECPs) by this microorganism. Although steatosis was found in some liver samples, no mortalities or clinical signs occurred in the inoculated fish. Clear cytotoxicity was observed after inoculation in the cell lines CHSE-214 and ASK, derived from salmonid tissues, but not in MDBK, which is of mammalian origin. The degree of cytotoxicity of the ECPs was different among the P. salmonis isolates tested. The isolate that evidenced the highest cytotoxicity in its ECPs exhibited only an intermediate virulence level after challenging fish with bacterial suspensions of the three P. salmonis isolates. Almost complete inhibition of the cytotoxic activity of ECPs was seen after proteinase K treatment, indicating their peptidic nature, and a total preclusion of the cytotoxicity was shown after their incubation at 50 °C for 30 min. Results show that P. salmonis can produce ECPs and at least some of them are thermolabile exotoxins that probably play a role in the pathogenesis of piscirickettsiosis.

Scrapie is an neurodegenerative and infectious disease that affects sheep and goats. The purpose of this study is to compare both tecniques, ELISA and IHC, to determine the application factibility giving the conditions of the laboratory in the country. To develop this assay, fourty obex samples were taken from sheep of the XII Region of Chile and were processed for both techniques ELISA and IHC. The results showed 100% of the samples negative for Scrapie, using both diagnostic methods. Based in obtained and previously reported results, ELISA technique can be recommended to use in massive screening, since yields reliable and rapid test results and IHC is a confirmatory technique. Both techniques are necessary in the creation of current epidemiological surveillance programs in Chile. ELISA and IHC are easily performed given the current laboratories conditions of the Chilean country.