984 resultados para Food storage pests
Resumo:
Active packaging is becoming an emerging food technology to improve quality and safety of food products. One of the most common approaches is based on the release of antioxidant/antimicrobial compounds from the packaging material. In this work an antifungal active packaging system based on the release of carvacrol and thymol was optimized to increase the post-harvest shelf life of fresh strawberries and bread during storage. Thermal properties of the developed packaging material were determined by differential scanning calorimetry (DSC) and thermogravimetric analysis (TGA). Volatile compounds in food samples contained in active packaging systems were monitored by using headspace solid phase microextraction followed by gas chromatography analysis (HS-SPME-GC-MS) at controlled conditions. The obtained results provided evidences that exposure to carvacrol and thymol is an effective way to enlarge the quality of strawberries and bread samples during distribution and sale.
Resumo:
Active packaging is becoming an emerging food technology to improve quality and safety of food products. One of the most common approaches is based on the release of antioxidant/antimicrobial compounds from the packaging material. In this work an antifungal active packaging system based on the release of carvacrol and thymol was optimized to increase the post-harvest shelf life of fresh strawberries and bread during storage. Thermal properties of the developed packaging material were determined by differential scanning calorimetry (DSC) and thermogravimetric analysis (TGA). Volatile compounds in food samples contained in active packaging systems were monitored by using headspace solid phase microextraction followed by gas chromatography analysis (HS-SPMEGC-MS) at controlled conditions. The obtained results provided evidences that exposure to carvacrol and thymol is an effective way to enlarge the quality of strawberries and bread samples during distribution and sale.
Resumo:
A major problem related to the treatment of ecosystems is that they have no available mathematical formalization. This implies that many of their properties are not presented as short, rigorous modalities, but rather as long expressions which, from a biological standpoint, totally capture the significance of the property, but which have the disadvantage of not being sufficiently manageable, from a mathematical standpoint. The interpretation of ecosystems through networks allows us to employ the concepts of coverage and invariance alongside other related concepts. The latter will allow us to present the two most important relations in an ecosystem – predator–prey and competition – in a different way. Biological control, defined as “the use of living organisms, their resources or their products to prevent or reduce loss or damage caused by pests”, is now considered the environmentally safest and most economically advantageous method of pest control (van Lenteren, 2011). A guild includes all those organisms that share a common food resource (Polis et al., 1989), which in the context of biological control means all the natural enemies of a given pest. There are several types of intraguild interactions, but the one that has received most research attention is intraguild predation, which occurs when two organisms share the same prey while at the same time participating in some kind of trophic interaction. However, this is not the only intraguild relationship possible, and studies are now being conducted on others, such as oviposition deterrence. In this article, we apply the developed concepts of structural functions, coverage, invariant sets, etc. (Lloret et al., 1998, Esteve and Lloret, 2006a, Esteve and Lloret, 2006b and Esteve and Lloret, 2007) to a tritrophic system that includes aphids, one of the most damaging pests and a current bottleneck for the success of biological control in Mediterranean greenhouses.
Resumo:
"Contract number AT(30-1)-2329, Task XII and under Contract number AT(30-1)-3006, Task XII."
Resumo:
Mode of access: Internet.
Resumo:
Typewritten.
Resumo:
"EPA 231-R-98-001."
Resumo:
Mode of access: Internet.
Resumo:
"May 1963"--T.p. verso.
Resumo:
Mode of access: Internet.
Resumo:
Literature cited: p. 37.
Resumo:
Earlier ed. by H. G. Scott.
Resumo:
Low temperature injury (LTI) of roses (Rosa hybrida L.) is difficult to assess by visual observation. Relative chlorophyll fluorescence (CF; F-v/F-m) is a non-invasive technique that provides an index of stress effects on photosystem 11 (PS 11) activity. This instrumental technique allows determination of the photosynthetic efficiency of plant tissues containing chloroplasts, such as rose leaves. In the present study, pre- and Post-Storage measurements of F-v/F-m were carried out to assess LTI in 'First Red' and 'Akito' roses harvested year round. Relationships between the pre-harvest environment conditions of temperature, relative humidity and photon flux density (PFD), F-v/F-m, and, vase life duration after storage are reported. After harvest, roses were stored at 1, 5 and 10 degrees C for 10 days. Non-stored roses were the control treatment. F-v/F-m ratios were reduced following storage, suggesting LTI of roses. However, reductions in F-v/F-m were not closely correlated with reduced vase life duration and were seasonally dependent. Only during winter experiments was F-v/F-m of roses stored at 1 degrees C significantly (P <= 0.001) lower compared to F-v/F-m of non-stored control roses and roses stored at 5 and 10 degrees C. Thus, the fall of F-v/F-m was due to an interaction of growing season and storage at 1 degrees C. Vase lives of roses grown during winter were significantly (P <= 0.001) shorter compared to roses grown during summer. Length of vase life was intermediate for roses grown during autumn and spring. Because of the lack of correlation between F-v/F-m and post-storage vase life it is concluded that the CF parameter F-v/F-m is nota practical index for assessing LTI in cold-stored roses. Higher PFD and temperature in summer were positively and significantly correlated with maintenance of post-storage FvIF ratios and longer vase life. It is suggested that shorter vase lives and lower post-storage F-v/F-m values after storage at 1 degrees C are consequences of reduced photosynthesis and smaller carbohydrate pools in winter-harvested roses. (c) 2004 Elsevier B.V All rights reserved.
Resumo:
Methyl ketones, aldehydes and free saturated fatty acids were measured in the headspace of samples of two indirectly processed and two directly processed Australian commercial UHT milks during room temperature storage for 16 weeks. The analytes were isolated using headspace solid phase microextraction and analysed by gas chromatography coupled with flame ionisation detection. All methyl ketones and aldehydes increased during storage, With free saturated fatty acids exhibiting little change. On average, the total methyl ketone and aldehyde concentrations in the indirectly processed UHT milks were higher than those in the directly processed samples. A strong correlation was found between the concentration of methyl ketones and various heat indices (furosine, lactulose and undenatured whey proteins) in the milk samples.