Upcycling Romaine lettuce outer leaves by infrared blanching and hot air drying.

Romaine lettuce outer leaves, as opposed to the more commonly marketed heart, are typically discarded and present an opportunity for upcycling as dried powders. Duquesne Romaine lettuce was evaluated to quantify and compare quality attributes of fresh outer and heart leaves, dried powders following hot air drying, and dried powders following an infrared (IR) blanching pretreatment before drying. Attributes measured for fresh leaves included moisture, water activity (Aw), color, total soluble phenolics (TSP), and antioxidant capacity (AC). Drying kinetics and time/energy saving through IR blanching were evaluated. Attributes measured for dried powders included moisture, Aw, color, true density, water vapor isotherms, TSP, AC, cadmium (Cd) content, and pesticide residues. TSP, AC, Cd, and pesticide residues were higher, whereas moisture content and Aw were lower in fresh outer versus heart leaves. Hot air drying reduced TSP and AC to 63.6% and 35.2% of fresh values, respectively, whereas IR blanching further reduced TSP and AC to 37.3% and 25.4% in outer leave powders. On the other hand, TSP and AC increased 237% and 151%, respectively, for unblanched heart powders. Higher increase of TSP than AC in heart leaf powder may indicate synthesis of phenolic compounds activated by abiotic stresses such as cutting and high temperatures at the initial drying stage. IR blanching resulted in significant time/energy savings for drying of outer leaves. Microbial loads were substantially reduced during drying, although microbial population on outer leaves were more resistant. Safe to eat outer leaf Romaine lettuce powders can be produced, assuming appropriate agricultural practices.

Capacitation increases glucose consumption in murine sperm.

Mammalian sperm acquire fertilization capacity in the female reproductive tract in a process known as capacitation. During capacitation, sperm change their motility pattern (i.e., hyperactivation) and become competent to undergo the acrosome reaction. We have recently shown that, in the mouse, sperm capacitation is associated with increased uptake of fluorescently labeled deoxyglucose and with extracellular acidification suggesting enhanced glycolysis. Consistently, in the present work we showed that glucose consumption is enhanced in media that support mouse sperm capacitation suggesting upregulation of glucose metabolic pathways. The increase in glucose consumption was modulated by bicarbonate and blocked by protein kinase A and soluble adenylyl cyclase inhibitors. Moreover, permeable cyclic adenosine monophosphate (cAMP) agonists increase glucose consumption in sperm incubated in conditions that do not support capacitation. Also, the increase in glucose consumption was reduced when sperm were incubated in low calcium conditions. Interestingly, this reduction was not overcome with cAMP agonists. Despite these findings, glucose consumption of sperm from Catsper1 knockout mice was similar to the one from wild type suggesting that other sources of calcium are also relevant. Altogether, these results suggest that cAMP and calcium pathways are involved in the regulation of glycolytic energy pathways during murine sperm capacitation.

Relationship between vaginal mucus conductivity and time of ovulation in weaned sows.

This study investigated whether changes in the vaginal electrical resistance (VER) of vaginal mucus of weaned sows during the first 7 d post-weaning are associated with time of ovulation. Time of ovulation was determined by ovarian ultrasound carried out from 91 to 146 h after weaning and at different seasons. Vaginal electrical resistance was measured at 20, 44, 68, 91, 96, 102, 115, 120, 126, 140, 146, and 164 h post-weaning and was found to decrease between 120 h and 31 h before ovulation and then increase until 40 to 50 h after ovulation. Duration and timing of the nadir was affected by the season (P < 0.01). Estrus was observed from day 4 after the lowest VER values. Ovulation occurred between late day 5 and late day 6, while VER values were still increasing. Ovulation was earlier in lower parity sows (P < 0.001). Compared to 0 h (ovulation time), VER was significantly lower from 50 to 5 h before ovulation in autumn and from 40 to 21 h in winter, but such differences were not seen in spring. Lowest VER value was not correlated with time of ovulation. It was concluded that VER increases before ovulation and, although this increase is influenced by the season, it cannot be used to accurately predict ovulation in weaned sows.

Au cours de la présente étude nous avons examiné si des changements dans la résistance électrique du mucus vaginal (REV) de truies sevrées durant les sept premiers jours post-sevrage sont associés avec le moment de l'ovulation. Le moment de l'ovulation était déterminé par échographie ovarienne effectuée entre 91 et 146 h après le sevrage et lors de différentes saisons. La REV fut mesurée aux heures post-sevrage suivantes : 20, 44, 68, 91, 96, 102, 115, 120, 126, 140, 146, et 164; et il fut noté que la REV diminuait entre 120 h et 31 h avant l'ovulation et augmentait par la suite jusqu'à 40 à 50 h après l'ovulation. La durée et le moment du nadir étaient affectés par la saison (P < 0,01). L'oestrus était observé à compter du jour 4 après la valeur la plus basse de REV. L'ovulation s'est produite entre tard le jour 5 et tard le jour 6, alors que les valeurs de REV augmentaient encore. L'ovulation survenait plus tôt chez les truies de parité moins élevée (P < 0,001). Comparativement à 0 h, la REV était significativement plus basse de 50 à 5 h avant l'ovulation à l'automne et de 40 à 21 h en hiver, mais ces différences n'étaient pas observées au printemps. La valeur la plus basse de REV n'était pas corrélée avec le moment de l'ovulation. Il fut conclu que la REV augmente avant l'ovulation et, bien qu'influencée par la saison, cette augmentation ne peut être utilisée pour prédire de manière précise l'ovulation chez les truies sevrées.(Traduit par Docteur Serge Messier).