Development of frozen-fried yam slices: Optimization of the processing conditions

The research performed on yam processing mainly concerns the production of crisps and flour. However, its transformation into deep-frozen French fries does not necessitate any other equipment than those used for potatoes. The industrial process of production of frozen French fries traditionally includes a pre-frying step. These steps contribute to the development of color and crispness, and the oil partially absorbed inhibits dehydration during the freezing step. The aim of this study was tooptimize frying conditions of deep-frozen fried yam (Dioscorea cayenensis var Kponan) slices. The effect of pre-frying time and temperature, final frying time and temperature on the oil uptake, texture, dry matter and colour of the fried yam slices has been studied. Frying conditions optimized with Box-Behnken experimental design were short pre-frying and frying conditions at high temperature characterized by prefryingtemperature at 157-170°C during 5-9s and frying temperature at 181-188°C for 2min 15s-2min 30s; or long pre-frying and frying conditions at low temperature characterized by pre-frying temperature at 150-158°C during 10-15s and frying temperature 170-177°C for 3-3min 15s. An adiabatic system was also developed by means of an insulator in which the core temperature of fried yam slices can be maintained constant at about 55°C after 15min of cooling, facilitating texture measurements at constant temperature. The present results may help in choosing the yam slices frying condition to be applied in order to achieve the desirable fried yamslices quality, required for protection against certain diseases like obesity. These models may also provide guidance as to how to control these quality parameters by altering four key environmental factors, pre-frying temperature and time and, final frying temperature and time. This process can also be commercialized and does not necessitate any other cost for equipment than those used for potatoes French fries and might be an interesting way of added value processing for this highly perishable yamtuber

Evaluation of λ-carrageenan, CpG-ODN, glycine betaine, Spirulina platensis and ergosterol as elicitors for the control of Zymoseptoria tritici in wheat

Wheat crops are constantly challenged by the pathogen Zymoseptoria tritici responsible for Septoria tritici Blotch (STB) disease. The present study reports the identification of five biocontrol compounds (λ-carrageenan, CpG-ODN, glycine betaine, Spirulina platensis and ergosterol) for the protection of wheat against STB in order to offer new alternative tools to farmers for sustainable crop protection. Screening of elicitors of wheat defenses was carried out through a succession of experiments: biocidal in vitro tests enabled to check for any fungicidal activities; glasshouse experiments allowed to determine the efficacy of a given compound in protecting wheat against STB; qRT-PCR biomolecular tests investigated the relative expression of 23 defense genes in treated versus untreated plants. We therefore demonstrated that λ-carrageenan, CpG-ODN, glycine betaine, Spirulina platensis and ergosterol are potential elicitors of wheat defenses. Foliar treatments with these compounds conferred protection of wheat by up to approximately 70 % against Z. tritici under semi-controlled conditions and induced both SA- and/or JA-dependent signaling pathways in the plant. These findings contribute to extend the narrow list of potential elicitors of wheat defenses against Z. tritici

Principaux modèles utilisés en régression logistique

Main models used in logistic regression. Regression is a commonly used technique for decribing the relationship between a response variable and one or more explanatory variables. When the response variable is a categorical variable, usual regression based on ordinary least squares should be replaced by logistic regression. Binary logistic regression should be used to perform a regression on a dichotomous response. Nominal polytomous logistic regression applies to a categorical response variable that has more than two levels with no natural ordering. And ordinal polytomous logistic regression is used when the response is a categorical variable that has more than two levels with a natural ordering. This note gives an overview of these logistic regression methods and describes three models commonly used when performing ordinal logistic regression. These models are illustrated by an example related to oak decline in the Walloon Region (Belgium)

Development Of Frozen-Fried Yam Slices: Optimization Of The Processing Conditions

The research performed on yam processing mainly concerns the production of crisps and flour. However, its transformation into deep-frozen French fries does not necessitate any other equipment than those used for potatoes. The industrial process of production of frozen French fries traditionally includes a pre-frying step. These steps contribute to the development of color and crispness, and the oil partially absorbed inhibits dehydration during the freezing step. The aim of this study was to optimize frying conditions of deep-frozen fried yam ( Dioscorea cayenensis var Kponan) slices. The effect of pre-frying time and temperature, final frying time and temperature on the oil uptake, texture, dry matter and colour of the fried yam slices has been studied. Frying conditions optimized with Box-Behnken experimental design were short pre-frying and frying conditions at high temperature characterized by pre-frying temperature at 157-170°C during 5-9s and frying temperature at 181-188°C for 2min 15s-2min 30s; or long pre-frying and frying conditions at low temperature characterized by pre-frying temperature at 150-158°C during 10-15s and frying temperature 170-177°C for 3-3min 15s. An adiabatic system was also developed by means of an insulator in which the core temperature of fried yam slices can be maintained constant at about 55°C after 15min of cooling, facilitating texture measurements at constant temperature. The present results may help in choosing the yam slices frying condition to be applied in order to achieve the desirable fried yam slices quality, required for protection against certain diseases like obesity. These models may also provide guidance as to how to control these quality parameters by altering four key environmental factors, pre-frying temperature and time and, final frying temperature and time. This process can also be commercialized and does not necessitate any other cost for equipment than those used for potatoes French fries and might be an interesting way of added value processing for this highly perishable yam tuber

Skeletal deformities induced by the intraperitoneal administration of deoxynivalenol (vomitoxin) in mice

SCOPUS: ar.jinfo:eu-repo/semantics/publishe

Impact of climatic factors on the release of E-β-caryophyllene from alginate beads

Description of the subject. Alginate beads that release semiochemical compounds are interesting biological control devices used to attract the natural enemies of aphids in infested crops. Little information, however, is available about the impact of climatic factors on the release of semiochemicals from this diffusive system. Objectives. The objective of this scoping study was to investigate the impact of temperature, relative humidity and wind speed, on the release of E-β-caryophyllene from alginate beads. Method. The impact of the three climatic factors on the release of E-β-caryophyllene from alginate beads was evaluated using a Box-Behnken experimental design and a laboratory scale volatile collection system. The influence of relative humidity on bead water content and size, with and without this semiochemical, was also investigated using a gravimetric method and an easy-to-use photographic device, respectively. Results. The results showed that an increase in temperature caused a significant increase in the E-β-caryophyllene release rate. Neither relative humidity nor airflow, however, had a significant effect on the release of this semiochemical when relative humidity and wind speed ranged from 33% to 75% and from 6.61 x 10-4 m·s-1 to 2.05 x 10-2 m·s-1, respectively. The isotherm curves obtained were characteristic of food products and biopolymer materials. The isotherm shapes were not modified by the incorporation of the semiochemical into alginate beads, and showed an important increase in water content when relative humidity values exceeded 85%. Fortunately, this water content increase did not affect bead size, which facilitates the calculation of E-β-caryophyllene release. Conclusions. The present study shows for the first time the impact of the three main climatic factors on the release of E-β-caryophyllene from alginate beads. It allows learning more about how these biological control devices operate in order to optimize future field trials

Study of the factors involved in the aggregation of Harmonia axyridis Pallas (Coleoptera: Coccinellidae)

info:eu-repo/semantics/publishe

Increased fecundity of malathion-specific resistant beetles in absence of insecticide pressure

Despite that resistance frequency is assumed to decline when selective pressure is relaxed, the stability of resistance frequency has been observed in some insects in the absence of insecticide. In the red flour beetle, Tribolium castaneum, the first case of malathion-resistance was reported in the early 1960s. The malathion-specific resistant phenotype has now almost completely replaced the susceptible one in red flour beetle populations. In the present study, several life-history traits that could influence the fitness of the insects were compared between insecticide-susceptible and malathion-specific resistant populations of the red flour beetle. On average, egg fertility and egg-to-adult development time did not differ between susceptible and resistant populations. However, the fecundity of resistant females was greater than that of susceptible ones. Generally, differences in development time between insecticide resistant and susceptible populations are considered as having more effect on fitness than do differences in fecundity. However, the observed increased female fecundity may participate, in combination with the previously observed increased male reproductive success, to the development and the stability of malathion-specific resistance in T. castaneum