N-nitrosamine inhibition by strawberry, garlic, kale, and the effects of nitrite-scavenging and N-nitrosamine formation by functional compounds in strawberry and garlic

Protective effect of whey cheese matrix on probiotic strains exposed to simulated gastrointestinal conditions

“…Mastication was simulated according to Hold, de Boer, Zuidema, and Maes (1995) and Choi, Chung, Lee, Shin, and Sung (2007), using a saliva solution prepared with 100 U mL −1 α-amylase (Sigma, Germany) and diluted in 1 mM CaCl 2 , whereas 1 M NaHCO 3 was used to adjust pH to 6.9; the simulated saliva was added to 25 g-samples at a rate of 0.6 mL min −1 for 2 min. The esophagus-stomach step encompassed 25 mg mL −1 pepsin (Sigma), prepared in 0.1 N HCl; this solution was added in equal-sized aliquots at each step during the whole gastric phase, at a rate of 0.05 mL mL -1 for a total of 90 min; and pH was decreased until 2, using 1 M HCl (Aura, 2005).…”

Influence of l-cysteine, oxygen and relative humidity upon survival throughout storage of probiotic bacteria in whey protein-based microcapsules

“…The typical conditions prevailing in the mouth, oesophagusestomach, duodenum and ileum were sequentially applied as follows: the mouth micro-environment (including mastication) was paralleled following the method of Höld, de Boer, Zuidema, and Maes (2000) and Choi, Chung, Lee, Shin, and Sung (2007), using a synthetic saliva solution prepared with 100 U mL À1 a-amylase in 1 mM CaCl 2 , and pH was adjusted to 6 using 1 M NaHCO 3 ; this simulated saliva was added at a rate of 0.6 mL min À1 . For the oesophagusestomach step, 25 mg mL À1 pepsin was prepared in 0.1 M HCl; this solution was added in equal-sized aliquots during the gastric phase, at a rate of 0.05 mL per mL or g of sample and pH was gradually decreased to pH 2 using 1 M HCl (Aura et al, 2005).…”

Contribution of different vegetable types to exogenous nitrate and nitrite exposure

“…Although nitrate is apparently non-toxic below maximum residue levels (MRLs), it may be endogenously transformed to nitrite which can react with amines and amides to produce N-nitroso compounds (Santamaria, 2006;Yordanov, Novakova, & Lubenova, 2001). These have been related to an increased risk of gastric, oesophageal, nasopharyngeal and bladder cancers (Choi, Chung, Lee, Shin, & Sung, 2007). For this reason the determination of nitrate and nitrite in food has received increased attention and several recent studies have addressed the dietary exposure of human population to these compounds (Menard, Heraud, Volatier, & Leblanc, 2008;Thomson, Nokes, & Cressey, 2007).…”