Short-term effects of a low glycemic index carob-containing snack on energy intake, satiety, and glycemic response in normal-weight, healthy adults: Results from two randomized trials

Background/Objectives: The potential positive health effects of carob containing snacks are largely unknown. Therefore, two studies were conducted to 1.firstly determine the glycemic index (GI) of a carob-snack compared to chocolate cookie containing equal amounts of available carbohydrates and 2.compare the effects of a carob vs. chocolate cookie preload consumed as snack before a meal on (a) short-term satiety response measured by subsequent ad libitum meal intake, (b) subjective satiety as assessed by visual analogue scales (VAS), and (c) postprandial glycemic response. Subjects/ Methods: Ten healthy, normal-weight volunteers participated in GI investigation. Then, 50 healthy, normal-weight subjects consumed, cross-over, in random order, the preloads as snack, with one-week wash-out period. Ad-libitum meal (lunch and dessert) was offered. Capillary blood glucose samples were collected at baseline, 2h-after breakfast-and-just-before-preload consumption, 2h-after-preload, 3h-after-preload and-just-before-meal-(lunch-and-dessert),1h-after-meal and 2h-after-meal consumption. Results The carob snack was low and chocolate cookie high GI foods (40vs.78 on glucose scale). Consumption of the carob preload decreased the glycemic response to a following meal and subjects’ feeling of hunger, desire to eat, preoccupation with food, and thirst between snack and meal, as assessed with the use of VAS. Subsequently, subjects consumed less amount of food (g) and had lower total energy intake at meal. Conclusions: The carob snack led to increased satiety, lower energy intake at meal and decreased post-meal glycemic response possibly due to its low GI value. Identifying foods that promote satiety and decrease glycemic response without increasing the overall energy intake may offer advantages to body weight and glycemic control

Investigating boundaries of survival, growth and expression of genes associated with stress and virulence of Listeria monocytogenes in response to acid and osmotic stress.

The objective of this study was to correlate the relative transcription of Listeria monocytogenes (strains C5, 6179) stress- (gad2, sigB) and virulence- (prfA) associated genes following habituation at twenty-five pH (4.8, 5.0, 5.2, 5.5, 6.4) and NaCl (2, 4, 6, 8, 10% w/v) combinations at 7 °C, with the survival against subsequent exposure to severe acid stress (pH 2.0 at 37 °C). Our findings pointed out the inter-strain variation governing growth inhibiting conditions (pH ≤5.0 and NaCl ≥6%), where C5 was less affected (a reduction of 2.0-3.0 log CFU/mL) than 6179 which was reduced by 4.0-6.0 log CFU/mL at the end of storage. Nevertheless, the higher the habituation at the growth permitting (pH ≥5.5; NaCl ≤4% w/v) or growth inhibiting conditions, the higher the acquired acid resistance or sensitization, respectively. At day 2, gad2 increased relative transcriptional levels are more related to elevated acid resistance, while at day 6 both gad2 transcriptional levels and upregulation of sigB were correlated to low log reductions and high DpH:2.0-values against severe acid stress. Regarding virulence, the increased transcriptional levels of prfA at day 2 were correlated to adverse pH and NaCl combinations, while prolonged stay in suboptimal conditions as well as exposure to severe acid stress resulted in general activation of the virulence regulator. Such data could definitely contribute in designing safe intervention strategies and additionally integrate -omics aspects in quantitative microbial risk assessment