Water sensitivity, antimicrobial, and physicochemical analyses of edible films based on HPMC and/or chitosan     

Sebti I  Chollet E  Degraeve P  Noel C  Peyrol E 《Journal of agricultural and food chemistry》2007,55(3):693-699

Several properties of chitosan films associated or not with hydroxypropylmethylcellulose polymer (HPMC) and HPMC films incorporating or not nisin and/or milk fat were studied. Nisin addition at a level of 250 microg mL-1 and likewise chitosan at 1% (w/v) concentration were efficient for total inhibiting Aspergillus niger and Kocuria rhizophila food deterioration microorganisms. HPMC and chitosan films were transparent, whereas nisin and/or fat incorporation induced a 2-fold lightness parameter increase and, consequently, involved more white films. Measurements of tensile strength, as well as ultimate elongation, showed that chitosan and HPMC initial films were elastic and flexible. High thermal treatments and additive incorporation induced less elastic and more plastic films. Water vapor transmission as far as total water desorption rates suggested that chitosan films were slightly sensitive to water. Water transfer was decreased by <60% as compared with other biopolymer films. Regarding its hydrophobic property, the capacity of fat to improve film water barrier was very limited.  相似文献   

Interactions between a non glycosylated human proline-rich protein and flavan-3-ols are affected by protein concentration and polyphenol/protein ratio   总被引：1，自引：0，他引：1  

Pascal C  Poncet-Legrand C  Imberty A  Gautier C  Sarni-Manchado P  Cheynier V  Vernhet A 《Journal of agricultural and food chemistry》2007,55(12):4895-4901

Interactions between salivary proline-rich proteins and tannins are involved in astringency, which is one of the most important organoleptic sensations perceived when drinking wine or tea. This work aimed to study interactions between a recombinant human salivary proline-rich protein, IB-5, and a flavan-3-ol monomer, epigallocatechin gallate (EGCG). IB-5 presented the characteristics of natively unfolded proteins. Interactions were studied by dynamic light scattering, isothermal titration microcalorimetry, and circular dichroism. The interaction mechanism was dependent on protein concentration. At low concentrations, a three-stage mechanism was evidenced. Saturation of the interaction sites (first stage) was followed by protein aggregation into metastable colloids at higher EGCG/protein ratios (second stage). Further increasing this ratio led to haze formation (third stage). At low ratios, a disorder-to-order transition of IB-5 structure upon binding was evidenced. At high protein concentrations, direct bridging between proteins and EGCG was observed, resulting in significantly lower aggregation and turbidity thresholds.  相似文献   

The parasitoid Dolichogenidea gelechiidivoris eavesdrops on semiochemicals from its host Tuta absoluta and tomato     

Ayelo  Pascal M.  Mohamed  Samira A.  Chailleux  Ana&#;s  Yusuf  Abdullahi A.  Pirk  Christian W. W.  Deletre  Emilie 《Journal of pest science》2022,95(2):633-652

Journal of Pest Science - Semiochemicals such as herbivore-induced plant volatiles (HIPVs) and host chemicals serve as communication signals for parasitoids searching for oviposition sites. The...  相似文献   

Genetic diversity of seeds from four German Douglas fir (Pseudotsuga menziesii) seed orchards     

Pakull  Birte  Eusemann  Pascal  Wojacki  Janine  Ahnert  Diana  Liesebach  Heike 《European Journal of Forest Research》2021,140(6):1543-1557

European Journal of Forest Research - In Germany, Douglas fir (Pseudotsuga menziesii Franco) is seen as a valuable species for future cultivation in times of climate change. Local seed production...  相似文献   

Characterisation of camel breeding practices in the Ansongo Region,Mali     

Bakary Traoré  Nassim Moula  Abdoulaye Toure  Bara Ouologuem  Pascal Leroy  Nicolas Antoine-Moussiaux 《Tropical animal health and production》2014,46(7):1303-1312

Despite its importance in Mali’s economy, camel breeding in the country remains poorly documented, impeding effective policy-making in this regard. This study consisted in a 3-month survey and aimed at characterising camel breeding systems in Ansongo, in the region of Gao, Mali. It highlights the diversity of strategies adopted by breeders and their evolutions. Supplementary feeding and veterinary care were seldom practised. In zones close to the Niger River, cattle were substituted to camels. Transhumance routes also are modified but mobility keeps its vital role in the breeding system. Important differences within the study region in the classification of camel breeds have been reported that will influence the implementation of a collective action for animal genetic improvement. The improvement goals should take the actual management, including mobility and the mixed nature of the herds into account.  相似文献   

Grow-out of sandfish Holothuria scabra in ponds shows that co-culture with shrimp Litopenaeus stylirostris is not viable     

Johann D. Bell  Natacha N. Agudo  Pascal Blazer  Dominique Pham 《Aquaculture (Amsterdam, Netherlands)》2007,273(4):509-519

We examined the potential for producing the large numbers of sandfish (Holothuria scabra) needed for restocking programmes by co-culturing juveniles with the shrimp Litopenaeus stylirostris in earthen ponds. Our experiments in hapas within shrimp ponds were designed to detect any deleterious effects of sandfish on shrimp, and vice versa. These experiments showed that a high stocking density of juvenile sandfish had no significant effects on growth and survival of shrimp. However, survival and growth of sandfish reared with shrimp for 3 weeks were significantly lower than for sandfish reared alone. Increased stocking density of shrimp also had a significant negative effect on survival and/or growth of sandfish. A grow-out trial of juvenile sandfish in 0.2-ha earthen ponds stocked with 20 shrimp post-larvae m^− 2, and densities of sandfish between 0.8 and 1.6 individuals m^− 2, confirmed that co-culture is not viable. All sandfish reared in co-culture were dead or moribund after a month. However, sandfish stocked alone into 0.2-ha earthen ponds survived well and grew to mean weights of ∼ 400 g within 12 months without addition of food. The grow-out trial demonstrated that there is potential for profitable pond farming of sandfish in monoculture. Further research is now needed to identify the optimal size of juveniles, stocking densities and pond management regimes.  相似文献   

Seasonal changes in sperm production and quality in the red porgy Pagrus pagrus (L.)     

Constantinos C Mylonas  Maria Papadaki  & Pascal Divanach 《Aquaculture Research》2003,34(13):1161-1170

Cultured red porgy Pagrus pagrus (L.) males (n=6) were sampled every 2 weeks for milt, in order to monitor changes in sperm quality parameters during a whole spawning period. On 11 January 2001, 60% of the fish were spermiating, increasing to 100% in mid‐February and dropping to 30% by mid‐April. Sperm density showed a slight increasing trend, with mean values ranging between 8.6 and 23.7×10⁹ spermatozoa mL^?1. Sperm motility percentage exhibited a significant improvement during the spawning season (analysis of variance (anova ) P=0.0001). The duration of forward motility for the major part of the monitoring period ranged between 2 and 4 min. Red porgy spermatozoa maintained their viability for many days after whole storage of milt at 4°C. During the monitoring period there were significant changes in the mean duration of sperm survival after cold storage, ranging from 5 to 12 days. The total volume of expressible milt was maximal on 28 March, increasing from a mean value of 1.7 mL to 5.3 mL kg^?1. Milt production of captive‐reared red porgy does not appear to be limiting, when compared with the volume of expressible milt produced by other cultured marine fishes.  相似文献   

Marennine,Promising Blue Pigments from a Widespread Haslea Diatom Species Complex     

Romain Gastineau  Fran?ois Turcotte  Jean-Bernard Pouvreau  Michèle Moran?ais  Jo?l Fleurence  Eko Windarto  Fiddy Semba Prasetiya  Sulastri Arsad  Pascal Jaouen  Mathieu Babin  Laurence Coiffard  Céline Couteau  Jean-Fran?ois Bardeau  Boris Jacquette  Vincent Leignel  Yann Hardivillier  Isabelle Marcotte  Nathalie Bourgougnon  Réjean Tremblay  Jean-Sébastien Deschênes  Hope Badawy  Pamela Pasetto  Nikolai Davidovich  Gert Hansen  Jens Dittmer  Jean-Luc Mouget 《Marine drugs》2014,12(6):3161-3189

In diatoms, the main photosynthetic pigments are chlorophylls a and c, fucoxanthin, diadinoxanthin and diatoxanthin. The marine pennate diatom Haslea ostrearia has long been known for producing, in addition to these generic pigments, a water-soluble blue pigment, marennine. This pigment, responsible for the greening of oysters in western France, presents different biological activities: allelopathic, antioxidant, antibacterial, antiviral, and growth-inhibiting. A method to extract and purify marennine has been developed, but its chemical structure could hitherto not be resolved. For decades, H. ostrearia was the only organism known to produce marennine, and can be found worldwide. Our knowledge about H. ostrearia-like diatom biodiversity has recently been extended with the discovery of several new species of blue diatoms, the recently described H. karadagensis, H. silbo sp. inedit. and H. provincialis sp. inedit. These blue diatoms produce different marennine-like pigments, which belong to the same chemical family and present similar biological activities. Aside from being a potential source of natural blue pigments, H. ostrearia-like diatoms thus present a commercial potential for aquaculture, cosmetics, food and health industries.  相似文献   

Off-Season Spawning of Eurasian Perch Perca Fluviatilis     

Herve Migaud  Jean-Noel Gardeur  Patrick Kestemont  Pascal Fontaine 《Aquaculture International》2004,12(1):87-102

This study was designed to determine the effects of the selection for body weight and of two final warming durations during an out-of-season reproductive cycle on gonad recrudescence, plasma steroid levels and spawning in Eurasian perch Perca fluviatilis males and females. Two different bodyweight classes (200–250 and 350–400 g) and two different warming periods (1 or 2 months) were studied.At the end of the chilling period, a significant effect of the selection for body weight was observed on gonad development whereas fish were the same age. According to higher levels in testosterone (12 ng mL^–1), a better development was recorded for smaller breeders (P < 0.05). A short water warming period up to 14°C (1 month v.s. 2 months) allowed higher rates of females with completed gonadogenesis (33–38% v.s. 7–8%) and spawning (31–33% v.s. 0%) (P < 0.05). Spontaneous out-of-season spawning (17 ribbons) and larvae were obtained. Relative fecundity was about 100 eggs g^–1 of female body weight. Five ribbons were partly fertilized with a rate ranging from 5 to 90%. These studies have shown that delayed spawning in Eurasian perch can be obtained by a temperature manipulation, but results are not sufficient because of low stimulation rate of females, low spawning rates and high heteroge-neity of fertilization rates. The effects of other environmental factors like photoperiod should be tested in further experiment to improve the protocol inducing out-of-season spawning production.  相似文献   

Using ecological trajectories to track long-term taxonomic and functional changes in benthic shallow soft-bottom communities (Bay of Saint-Brieuc,English Channel)     

Anthony Sturbois  Gaëtan Cormy  Alexandre Le Moal  Gauthier Schaal  Caroline Broudin  Eric Thiébaut  Alain Ponsero  Patrick Le Mao  Auriane Jones  Pascal Riera  Olivier Gauthier  Nicolas Desroy 《水产资源保护:海洋与淡水生态系统》2021,31(11):3013-3033

1. Taxonomic and functional trajectories of benthic assemblages were studied in shallow soft-bottom sediments in the bay of Saint-Brieuc (Western English Channel). Changes were assessed at different spatial and temporal scales using a macrobenthic dataset based on 38 stations sampled in 1987 and 2019, coupled with data from one station sampled annually between 2005 and 2019 as part of the European Water Framework Directive monitoring programme.
2. Taxonomic trajectories indicated 1) changes in the structure and distribution of benthic assemblages, 2) an homogenization of the assemblages, and 3) significant functional shifts.
3. Fishing activities and nutrient enrichment are probably strong drivers of the observed changes, as suggested by the higher mortality rate of fragile, flexible, tubiculous and burrowing species, and the increase in the abundance of opportunistic species in the assemblages. Certain populations of macroinvertebrates seem jointly controlled by climate change and by the aforementioned local factors of disturbance.
4. The Community Trajectory Analysis framework appears as a new and interesting method to track ecological changes in marine ecosystems by measuring change with respect to a baseline state, to help define ecological recovery (station returning to the initial ecological state) and departure (station presenting increased changes over time), and to analyse trajectory similarity.
5. According to the degradation of habitat over time, we identify the need for the implementation of knowledge-based conservation strategies, especially within Natura 2000 sites.

  相似文献