Two experiments were conducted to evaluate the effect of formaldehyde vaporization of a hatcher on the tracheal epithelium of chick embryos, and on the production performance and behaviour of commercial broiler chicks. In experiment 1, chick embryos were exposed to 23.5 ppm of formaldehyde vapour during the last 3 days of incubation. Tracheal samples were taken at 0, 6, 30 and 54 h after exposure to formaldehyde and examined by scanning electron microscopy for pathological changes. Observable lesions included excessive accumulation of mucus, matted cilia, loss of cilia and sloughing of the epithelium. The lesions were more severe in chicks exposed for 54 h as compared to those exposed for 6 or 30 h. In experiment 2, 60 chicks that had been exposed to formaldehyde vapour as above and 60 control chicks were used to investigate the effect of formaldehyde fumigation on production performance and behaviour. Formaldehyde vaporization resulted in higher weekly (days 0-6 and 21-27) and total (days 0-41) feed intake and poorer weekly (days 0-6, 7-13, 21-27 and 28-34) and overall (days 0-41) feed conversion ratios. Body weight, mortality and behaviour (eating, drinking, sitting and standing activities) were not affected by formaldehyde fumigation.
Fresh-cut pineapple has experienced an increase in demand due to its great health benefits and is rich in vitamins A, B and C. Moreover, pineapple is known as a source of the enzyme bromelain, which has therapeutic applications, such as reducing inflammation, improving digestion and treating osteoarthritis. However, bromelain generally affects the pineapple’s flavour and is less preferred by consumers due to the uncomfortable prickling and tingling sensations it brings. In the present study, two types of gases and their combination, nitrogen (N2) and carbon dioxide (CO2), were used to evaluate their impacts on reducing the tingling and prickling sensations, as well as maintaining the postharvest qualities of fresh-cut pineapple stored at 5°C for 12 days. The parameters being evaluated were the bromelain enzyme activity, flesh colour, ascorbic acid concentration, flesh firmness, soluble solids concentration (SSC), titratable acidity (TA) and sensory evaluation. No significant differences were recorded for all parameters tested. Based on the sensory evaluations, all the attributes, such as colour, aroma, texture, sweetness, sourness, tingling and prickling sensations, and overall acceptance were not affected by the different gases application. Even though no apparent effect was observed, the 30 panellists preferred the aforementioned attributes, except sourness. In conclusion, the fumigation treatments with N2 and CO2 gases were not effective in reducing the tingling and prickling sensations of pineapples cv. Morris.