Enzymatic browning reactions in apple and apple products Nicolas, J.J; Richard-Forget, F.C; Goupy, P.M ...
Critical reviews in food science and nutrition,
(1994), 1/1/1994, 1994, 1994-00-00, 1994-01-00, 19940101, Letnik:
34, Številka:
2
Journal Article
Recenzirano
This review examines the parameters of enzymatic browning in apple and apple products that is, phenolic compounds, polyphenoloxidases, and other factors ascorbic acid and peroxidases), both ...qualitatively and quantitatively. Then the relationships between intensity of browning and the browning parameters are discussed, including a paragraph on the methods used for browning evaluation. Finally, the different methods for the control of browning are presented
Introduction De nombreuses études rapportent une corrélation inverse entre apport alimentaire et/ou taux plasmatiques de β-carotène et IMC, tour de taille (TT) ou insulino-résistance, conséquence ...possible d’une alimentation pauvre en fruits et légumes, d’un stockage accru dans le tissu adipeux, ou d’une majoration de l’inflammation et du stress oxydant augmentant les besoins en micronutriments anti-radicalaires ; un effet du β-carotène sur l’adipogenèse et/ou la résistance à l’insuline ne peut toutefois être exclu. Très peu d’études ont été menées spécifiquement chez les obèses. Patients et méthodes Étude transversale incluant 108 obèses non diabétiques (26 H/82 F ; 40,7 ± 12,5 ans ; IMC 40,0 ± 6,3 kg/m2 ; TT 116,6 ± 11,1 cm) bénéficiant d’une HGPO et du dosage de certaines adipokines (adiponectine, leptine, PAI-1, TNF-α, IL-1) et du β-carotène plasmatique (HPLC). Résultats Les concentrations de β-carotène sont significativement plus faibles chez les hommes et les fumeurs actifs. En analyse univariée, les concentrations de β-carotène sont corrélées inversement à l’IMC (r = - 0,27 ; p < 0,05), au HOMA-IR (r = - 0,32 ; p < 0,001) et au PAI-1 (r = - 0,24 ; p < 0,05) et positivement à l’âge (r = 0,38 ; p < 0,0001), au HDL (r = 0,24 ; p < 0,05) et à l’adiponectine (r = 0,26 ; p < 0,05). En régression multiple, la relation inverse entre β-carotène plasmatique et HOMA-IR est perdue après ajustement pour l’IMC ou le TT. A contrario, la relation inverse entre β-carotène et adiponectine persiste après ajustement pour l’IMC, le TT, le sexe, l’âge et le tabagisme actif (p < 0,05). Conclusion Chez ces obèses non diabétiques, on retrouve une association positive entre les concentrations de β-carotène et d’adiponectine indépendante du sexe et du degré d’adiposité globale et abdominale, suggérant un effet favorable du β-carotène sur la sensibilité à l’insuline. Les bénéfices du β-carotène pourraient être liés à ses propriétés anti-oxydantes, ou à une modulation de l’inflammation ou de l’expression de certaines adipokines, soit directement soit via son activité provitaminique A.
Phenolic compounds and polyphenol oxidase (PPO) activity in the fruits of 11 apple cultivars before and after bruising were studied in relation to their susceptibility to browning. The degree of ...browning has been determined by the simultaneous measurements of soluble (absorbance at 400 nm) and insoluble (lightness) brown pigments. The sum of these two expressing the extent of browning, closely correlated with the amount of phenolics (hydroxycinnamic derivatives and flavan-3-ols) degraded. Maturity did not appear to greatly influence the development of browning
Plant foodstuffs are an important source of a wide variety of flavonoids with protective properties on low-density lipoprotein oxidation as shown in vitro and in some human and animal experiments. ...Increasing information is available concerning the absorption and pharmacokinetics of these molecules, but their long-term protective effect on coronary heart disease still needs further investigation.
Objective: Consumption of fruit and vegetables (F&V) may play a role in the fight against overweight. The aim of the current study was to validate the link between consumption of F&V with overweight ...and biological impact. The Algerian context is a very rapid transition with a high prevalence of overweight and low consumption of F&V. Methodology: Qualitative and quantitative surveys were conducted on 421 persons in urban (200) and rural (200) areas. Experimentation on 40 persons in Adj El Mechri (South Algeria): Distribution of 400 g/capita/day of fruit and vegetables during 2 months. Results: (i) Link between consumption of F&V and the prevalence of overweight is not as obvious as it seems. Three types of people emerge: (a) urban people with a high level of F&V consumption and a normal body mass index, (b) the illiterate urban people with a low consumption of F&V and prone to obesity, (c) the rural elderly, primary school level people with a pre-obese status. (ii) Some physiological and behavioural impacts of increased consumption of F&V were validated: vitamins E and B9 have increased; blood pressure was improved; pre-obese people lost weight while obese persons have increased their weight because the quantity of F&V consumed was added to the usual ration. (iii) Increased availability of F&V was appreciated and did not disrupt the behaviours. Low consumption of F&V was due to their limited access (low income, high prices, low availability and lack of variety).
Health benefits of fruits and vegetables could be attributed to the presence of a large diversity of phytochemicals, including carotenoids. The bioactivities of carotenoids greatly depend on their ...bioavailability that could be modulated by the presence of other dietary constituents. Because citrus juices contain diverse antioxidant phytochemicals, the effects of flavonoids and ascorbic acid on intestinal carotenoid uptake were investigated. Experiments were conducted by using a Caco-2 cell monolayer exposed to micelles enriched in β-cryptoxanthin b-CX and β-carotene b-C, in the presence of hesperetin HES, hesperidin HES-G, naringenin, acid ascorbic AA and iron. After 5 or 24 h incubation, both HES-G and HES significantly increased b-CX and b-C uptake by around 1.6-fold. Interestingly, AA was shown to eliminate the enhancing effect of HES-G by decreasing significantly the cellular uptake of b-CX and b-C by 10% after 5 h incubation. Iron decreased the carotenoid uptake, but HES-G was shown to counteract the iron effect, certainly due to its iron-chelating activity.
Identification of Some Phenolics in Pear Fruit Oleszek, Wieslaw; Amiot, Marie J; Aubert, Serge Y
Journal of agricultural and food chemistry,
06/1994, Letnik:
42, Številka:
6
Journal Article
Recenzirano
Four hydroxycinnamic acid esters and eight flavonol glycosides were isolated and identified in pear fruit. By chemical and spectral methods the cinnamics were identified as 5'-caffeoylquinic, ...p-coumaroylquinic, p-coumaroylmalic, and dicaffeoylquinic eaters. The mixture of flavonols included three quercetin and five isorhamnetin glycosides. The quercetin 3-O-glycosides were identified as rutinoside, glucoside, and malonyl glucoside, and the isorhamnetin 3-O-glycosides included rutinoside, galactorhamnoside, glucoside, malonyl galactoside, and malonyl glucoside
Model solutions containing chlorogenic acid (CG) and (-)-epicatechin (EP), and phenolics from nine apple cv., were oxidized with apple polyphenoloxidase (PPO). Browning was determined by absorbance ...at 380700 nm, and transformed into CIE L*, a* and b*. Multilinear correlations were established between initial and degraded amounts of each phenolic. In model solutions of CG and EP, color values and A400 correlated strongly with initial and oxidized CG and EP. Both phenolics contributed to decrease in LF and increase in A400. Increase in CG increased a*, but EP had little effect. The impact of increased EP on bF was two to three times higher than for CG. In each phenol class (hydroxycinnamic (HD), flavan-3-ol (FA), flavonol (FO) and dihydrochalcone (DC) derivatives), degraded amounts were increased or decreased by increasing amounts of other classes. Besides major phenolics, HD (mainly CG) and FA (mainly EP and procyanidin B2), FO and DC, appeared to affect color development
We investigated the fractionation of an alfalfa white protein concentrate (AWPC) hydrolysate by electrodialysis with ultrafiltration membranes (EDUF), a novel membrane technology. The latter, based ...on the separation mechanisms of conventional membrane filtration (size) and electrophoresis (electrical charge), is suitable for the large scale fractionation of valuable molecules from complex feedstocks. Two ultrafiltration membranes were stacked in an electrodialysis cell to allow a configuration with two recovery compartments (KCl 1 and 2). The effect of pH (3 and 9) on the migration of basic/cationic and acid/anionic peptides was studied in these conditions. It was established that EDUF allows the simultaneous separation and concentration of charged peptides with a transport rate up to 7.3
g/(m
2
h). Amongst a total of 70 peptides contained in the AWPC hydrolysate, only 8 peptides were found in the separated adjacent recovery solutions (KCl 1 and 2). Amongst these eight migrating peptides, four significant peptides were recovered in the basic KCl 1 and one antihypertensive peptide identified as VW was recovered in KCl 2. The maximum transmission rate recorded for a peptide was 18.23%. Furthermore, apart from the selective separation, our results showed that EDUF could overcome some of the fouling problems in the conventional pressure-driven processes.
