Effect of apple particle state on the release of volatile compounds in a new artificial mouth device

Varying the crushing parameters in a model mouth apparatus gave different crushed apple samples, which were compared to apples crushed in the human mouth by six people. An image analysis method was developed to measure the similarity between apple particles after crushing in the artificial mouth and in the human mouth. Thus, experimental conditions were determined that produced fruit in a state closest to that obtained after mastication in a human mouth. The influence of these different conditions on the quantity of released volatile compounds was then studied.     

Stability of barley and malt lipid transfer protein 1 (LTP1) toward heating and reducing agents: relationships with the brewing process

Barley lipid transfer protein (LTP1) is a heat-stable and protease-resistant albumin that concentrates in beer, where it participates in the formation and stability of beer foam. Whereas the barley LTP1 does not display any foaming properties, the corresponding beer protein is surface-active. Such an improvement is related to glycation by Maillard reactions on malting, acylation on mashing, and structural unfolding on brewing. The structural stability of purified barley and glycated malt LTP1 toward heating has been analyzed. Whatever the modification, lipid adduction or glycation, barley LTP1s are highly stable proteins that resisted temperatures up to 100 degrees C. Unfolding of LTP1 occurred only when heating was conducted in the presence of a reducing agent. In the presence of sodium sulfite, the lipid-adducted barley and malt LTP1 displayed higher heat stability than the nonadducted protein. Glycation had no or weak effect on heat-induced unfolding. Finally, it was shown that unfolding occurred on wort boiling before fermentation and that the reducing conditions are provided by malt extract.     

Assessing evidence of a potential Salmonella transmission across the poultry food chain

Enhanced Salmonella surveillance programmes in poultry were implemented in all European Member States, with minimum prevalence targets for a list of targeted serotypes to safeguard food and public health. Based on the Belgian Salmonella surveillance programme and focusing on poultry, the overarching aim of this study was to highlight possible Salmonella transmissions across the food chain (FC). For this purpose, firstly, the prevalence patterns of Salmonella (targeted and the most prevalent non-targeted) serotypes along the FC were described over time. Secondly, the effectiveness of the control measures against vertical transmission (breeders to 1-day-old broiler and layer chicks) was indirectly assessed by looking into the odds of targeted serotypes detection. Thirdly, it was appraised if Salmonella prevalence can significantly increase during broilers and layers production. In addition, it was tested if being tested negative at the end of production in broilers when tested positive at the entrance is serotype dependent (targeted vs. non-targeted serotypes). Results showed that, firstly, the prevalence patterns of the listed serotypes were inconstant over time and across the FC. Secondly, the odds of Salmonella targeted serotype detection in 1-day-old broiler and in 1-day-old layer flocks were lower than in breeder flocks while, thirdly, infection during broiler and layer production can lead to significant increase in positivity in subsequent samples. Finally, being infected by a targeted or by non-targeted serotype at the entrance of the flock poorly reflects the Salmonella status at the end of production. Note that this study did not make a distinction between the different sources of contamination and the effects of sampling methods and isolation methods should be subject to further investigation.     

Severe modifications in source-sink ratio influence the susceptibility of bananas to crown rot and its phenolics content

Banana susceptibility to crown rot is influenced by many biotic and abiotic preharvest factors, which include source-sink (So-Si) ratio modifications through trimming of leaves and fruit. Banana plant's resistance to biotic stress has been previously correlated to its phenolic content; it is hypothesized that the crown's phenolic content may influence the fruit's susceptibility. The aim of this work was to investigate the influence of severe So-Si ratio modifications, via the removal of leaves and fruit, and the involvement of phenolics in the fruit's susceptibility to crown rot. Fruit susceptibility was evaluated 13 days postinoculation (13 dpi) with Colletotrichum musae. Banana crowns obtained on the day of harvest before inoculation (dhbi) and 13 dpi were analysed for changes in phenolics using GC-MS, HPLC, and LC-MS devices. Severe So-Si ratio modifications had a significant effect (p <.001) on susceptibility, fruits of low So-Si ratio being most susceptible. It also significantly influenced (p < .001) some tree and fruit characteristics. The less susceptible (S−) crowns had higher amounts of phenolics compared to the more susceptible (S+) ones. Catecholamines were identified as the major phenolics in banana crown, notably dopamine compared to norepinephrine and normetanephrine. Hydroxycinnamic acids (ferulic acid and its derivatives) were significantly accumulated (p <.001) the dhbi in S− crowns compared to S+ crowns, but decreased 13 dpi. Phenolics have a possible role in the biochemical defence of banana crown and could be used by producers as a chemical criterion for estimation of the level of banana's susceptibility to crown rot.