Ultrasmall fluorescent nanoparticles derived from roast duck: their physicochemical characteristics and interaction with human serum albumin

Abstract

Fluorescent nanoparticles (FNPs) produced from roast meat have drawn widespread attention due to their potential hazards to human health. In this paper, the presence of ultrasmall FNPs in roast duck and their interaction with human serum albumin (HSA) were reported. The processing-induced FNPs have an average size of 1.3 nm with a relative fluorescence quantum yield of 4.4%. X-ray photoelectron spectroscopy showed that the FNPs are composed of carbon (70.48%), nitrogen (6.25%), oxygen (22.17%) and sulfur (1.11%), with hydroxyl, carboxyl and amino groups present on their surface. The presence of FNPs could cause fluorescence quenching of HSA, which was ascribed to the static quenching mechanism via the electrostatic interaction as analyzed by isothermal titration calorimetry. The α-helix contents of HSA decreased after the addition of FNPs, demonstrating that these processing-induced FNPs could cause structural alteration of HSA. These results provided insights into the formation of nanoparticles in roast duck, and offered important information about the binding mechanism of these nanoparticles with HSA, which may have physiological implications.

Interaction of Mitoxantrone-Loaded Cholesterol Modified Pullulan Nanoparticles with Human Serum Albumin and Effect on Drug Release

“…The peak position and peak shape of the fluorescence emission peaks for HSA, HSA and MTO, HSA and CHP NPs, and HSA and MTO-CHP NPs were basically almost similar (Figures 4(a) and 4(b)). The maximum value of fluorescence emission intensities was at 342 nm owing to the effect of the tryptophan residue in the HSA molecule [27], so CHP NPs and HSA formed a complex. When the NPs were completely combined with HSA and at the beginning of the process, the fluorescence intensity for HSA was greatly decreased, and MTO-CHP NPs more strongly quenched HSA fluorescence intensity than did CHP NPs.…”

“…HSA contains a tryptophan that is excited in the ultraviolet region to emit fluorescence, forming a fluorescent spectrum. When other molecules interact with HSA, tryptophan fluorescence may change, depending on the effect of this interaction on protein conformation [27,28]. HSA and MTO, CHP NPs, and MTO-CHP NPs were mixed and reacted at a molecular ratio of 3.6 : 1 (HSA: 1 5 × 10 −5 mol/L).…”

Endogenous Fluorescence Carbon Dots Derived from Food Items

“…This might be the initial motivation to find CDs in food items. To date, fluorescent CDs have been discovered in various kinds of foods items, such as roasted duck, 29 mature vinegar, 30 lamb chops, 24 , 31 honey, 32 pike eel, 33 salmon, 25 , 34 canned yellow croaker, 26 beer, 35 bread, 20 Coca-Cola (Pepsi-Cola), 36 kvass, 22 coffee, 21 grilled hamburger, 37 pizza, 38 caramels, 20 and barbecue 39 . The varieties and properties of CDs from food items are summarized in Table 1 .…”

“… 26 Duck Roasted at 170°C for 60 min ~1.3 C=O; C=C; CO–NH 4.4 – Cong et al. 29 Mature vinegar Isolated from Chinese mature vinegar 0.5–2.5 -OH;C=O; –COOH 5.71 – Cao et al. 30 Glucose and lysine Products of the Maillard reaction 2.3–6.8 O-H; O=C–O; C–O; O=C–O 16.30 Cell viability decreased to 80% after treatment with 10 mg mL −1 CDs Li et al.…”

“… 20 was also a good example attributed to the pyrolytic reaction between food additive and starch during baking. Recently, our group has proven the universal formation of CDs in roast protein foods, including beef patties, 37 grilled fish, 33 , 49 baked lamb, 24 , 31 popular pizza, 38 roasted duck, 29 and chicken. 40 All the results demonstrated that CDs can be easily produced in normal thermal processing of foods.…”