Gallic Acid and Quercetin as Intelligent and Active Ingredients in Poly(vinyl alcohol) Films for Food Packaging

Abstract

Gallic acid (GA) and quercetin (QC) were used as active ingredients in poly(vinyl alcohol) (PVA) film formulations obtained by solvent casting process. The effect of two different percentages (5 and 10 % wt.) on morphological behavior, thermal stability, optical, mechanical, and release properties of PVA were investigated, while migration with food stimulants and antioxidant properties were tested taking into account the final application as food packaging systems. The results showed how different dispersability in PVA water solutions gave different results in term of deformability (mean value of ε PVA/5GA = 280% and ε PVA/5QC = 255%, with 190% for neat PVA), comparable values for antioxidant activity at the high contents (Radical Scavenging Activity, RSA(%) PVA/10GA = 95 and RSA(%) PVA/10QC = 91) and different coloring attitude of the polymeric films. It was proved that GA, even if it represents the best antioxidant ingredient to be used with PVA and can be easily dispersed in water, it gives more rigid films in comparison to QC, that indeed was more efficient in tuning the deformability of the PVA films, due the presence of sole hydroxyl groups carrying agent. The deviation of the film coloring towards greenish tones for GA films and redness for QC films after 7 and within 21 days in the simulated conditions confirmed the possibility of using easy processable PVA films as active and intelligent films in food packaging.

Poly(vinyl alcohol)-Based Biofilms Plasticized with Polyols and Colored with Pigments Extracted from Tomato By-Products

“…High peaks were identified around 1000 cm −1 especially for the samples that contain plasticizers (1087 and 1141 cm −1 for PVOH+PDO, 1087 and 1139 cm −1 for PVOH+PDO+TP, 1085 and 1141 cm −1 for PVOH+BDO, and 1083 and 1139 cm −1 for PVOH+BDO+TP. In addition, 1037 and 1141 cm −1 for PVOH+Gly, 1039 and 1139 cm −1 for PVOH+Gly+TP), a fact that indicates the presence of C-O bonds specific to diols and triols [66,74,76]. The presence in TP of compounds such as β-carotene and lutein can be associated with the small peaks observed around 1500 cm −1 for the samples supplemented with TP (1566 cm −1 for PVOH+TP and 1568 cm −1 for PVOH+PDO+TP/PVOH+BDO+TP/PVOH+Gly+TP) peaks that indicate C=C bonds [77].…”

“…All samples recorded two small signals between 2800 and 3000 cm −1 (2906 and 2939 cm −1 for PVOH/PVOH+PDO/PVOH+BDO, 2908 and 2395 cm −1 for PVOH+PDO+TP/PVOH+BDO+TP, 2910 and 2937 cm −1 for PVOH+Gly, and 2915 and 2933 cm −1 for PVOH+Gly+TP) that are attributed to C-H stretches [75]. The peaks situated between 1500 and 1700 cm −1 (1564 and 1656 cm −1 for PVOH/PVOH+BDO, 1566 and 1654 cm −1 for PVOH+PDO, 1564 and 1641 cm −1 for PVOH+Gly, 1566 and 1660 cm −1 for PVOH+TP, 1568 cm −1 for PVOH+PDO+TP, 1568 and 1662 cm −1 for PVOH+BDO+TP, and 1568 and 1654 cm −1 for PVOH+Gly+TP) are related to the presence of C=C vibration, as the literature points out [76,77]. High peaks were identified around 1000 cm −1 especially for the samples that contain plasticizers (1087 and 1141 cm −1 for PVOH+PDO, 1087 and 1139 cm −1 for PVOH+PDO+TP, 1085 and 1141 cm −1 for PVOH+BDO, and 1083 and 1139 cm −1 for PVOH+BDO+TP.…”

Active Packaging—Poly(Vinyl Alcohol) Films Enriched with Tomato By-Products Extract

“…The physical measurements of the solid PVA-based films; the shown data represent the mean value of three replicates with the standard deviation (±). FTIR is a useful method to identify specific molecular structures or the vibration of functional groups from certain matrices [73,74]. For the present study, FTIR analysis was performed for PVA-based films supplemented with TBE ( Figure 6) in order to observe the influence of tomato waste-based extract on the PVA formulations.…”

Evaluation of the protective effects of quercetin and gallic acid against oxidative toxicity in rat’s kidney and HEK-293 cells

“…Furthermore, several studies with many phytochemicals including quercetin (QUE), hesperetin, naringenin, myricetin and morin have established that these flavonoids have both antioxidant and pro-oxidant effects at different doses [ 12 , 13 ]. The health benefits of GAL and QUE facilitate them to be used as antioxidant ingredients in poly (vinyl alcohol) film formulations for food packaging [ 14 ].…”