Production of methylcellulose films functionalized with poly-ε-caprolactone nanocapsules entrapped ß-carotene for food packaging application.

Nowadays, there is a worldwide demand in the production of innovative packaging that release active compounds to increase the shelf life of perishable food products. Therefore, this study produced methylcellulose films functionalized with poly-ε-caprolactone nanocapsules entrapped ß-carotene. The nanoparticles were produced by the nanoprecipitation method, and 10, 30, and 50 % of nanoparticles colloidal solution was added in the methylcellulose filmogenic solution. The films were characterized by the mechanical, physicochemical properties, antioxidant activity, and release of ß-carotene from the polymeric matrix to a food simulant. The results demonstrated satisfactory mechanical properties; however, the addition of nanoparticles decreased the Young's Modulus and increased the elongation at break. Regarding light transmission, the incorporation of ß-carotene nanoparticles promoted a decrease in the percentage of ultraviolet ray's transmittance through the film matrix, as well as visible light. The incorporation of nanoparticles improved the antioxidant activity of the films, which was proportional to the concentration of ß-carotene used in the formulation. The release of ß-carotene reached a maximum value of 10.93 µg g-1 film containing 70 % nanoparticles, which was a desired profile for food application. Finally, the methylcellulose films functionalized with poly-ε-caprolactone nanocapsules can release ß-carotene, and therefore, can be considered as a novel nanomaterial for food conservation, with a potential to increase the shelf life of perishable food products.

Development and Characterization of Poly-ε -caprolactone Nanocapsules Containing β -carotene Using the Nanoprecipitation Method and Optimized by Response Surface Methodology

Abstract Nanoparticles demonstrate an important role in the protection of bioactive compounds from external factors such as temperature, oxygen and light. In this study, poly-ε-caprolactone (PCL) nanoparticles entrapped β-carotene was produced using the nanoprecipitation method. Firstly, was evaluated the lipophilic surfactant effect and carrier agent of the active compound in the nanocapsules formulation. After choosing the most stable formulation, the nanocapsules production was optimized using β-carotene, caprylic/capric triglycerides (CCT) and soybean lecithin. Response surface methodology (RSM) was adopted to evaluate the influence of soy lecithin concentration, volume of CCT and β-carotene concentration in the particle size, zeta potential, polydispersity index (PDI), encapsulation efficiency and recovery. Formulations containing soy lecithin and CCT demonstrated better stability comparing to the other formulations tested. The nanoparticle formulations presented an optimized particle size below 200 nm, PDI lower than 0.1 and encapsulation efficiency above 95%. Based on the results obtained, the optimum conditions to prepare PCL nanocapsules were 0.2160 mg/mL of β-carotene, 232.42 μL of CCT and 2.59 mg/mL of soy lecithin, suggesting an applicability to promote controlled released of β-carotene in food system.

Evaluation of oxidative stability of mayonnaise containing poly ε- caprolactone nanoparticles loaded with thyme essential oil

Suspensions of poly ε-caprolactone (PCL) nanoparticles loaded with thyme essential oil were prepared as a natural antioxidant in mayonnaise. Mean particle size was 204.9 ± 2.7 and 240.0 ± 5.5 nm respectively for nanoparticles prepared with PCL alone (NP-C) and for those loaded with thyme essential oil (NP-T). The polydispersity index indicated a homogeneous distribution of all particles, with no significant difference between NP-C and NP-T samples. The nanoparticles showed a large negative charge evidenced by zeta potential rates, indicating high physical stability. The use of PCL as a polymer provided high encapsulation efficiency for thyme essential oil (91.15 ± 2.12 %). DPPH (2,2-diphenyl-1-picrylhydrazyl) method determined IC50 rates were 476.4 ± 33.6 and 483.5 ± 20.4 µg mL-1respectively for unencapsulated oil and for NP-T, evidencing pronounced antioxidant activity. NP-C, NP-T and synthetic antioxidant butylhydroxytoluene (BHT) were applied to samples of mayonnaise and their oxidative stability evaluated for eight days in an oven at 63 ± 3ºC. Results of hydroperoxide value (HP) and thiobarbituric acid reactive substances (TBARS) showed that NP-T had a similar performance as synthetic antioxidant BHT in the prevention of mayonnaise lipid oxidation

Antioxidant and antimicrobial methylcellulose films containing Lippia alba extract and silver nanoparticles.

Methylcellulose is a biopolymer, which can be used in the preparation of films for the production of biodegradable active packaging. In this work, the methylcellulose films containing biosynthesized silver nanoparticles (AgNPs) were developed using Lippia alba extract. The physico-chemical, antioxidant, and antimicrobial properties of the films were studied. The insertion of Lippia alba compounds was verified using infrared spectroscopy (FTIR), with the appearance of a band at 1595 cm-1 and 1410 cm-1 which is characteristic of CCC stretches of the aromatic ring, and the increase in the hydrophobicity of the films containing the extract in relation to the control film. The films containing AgNPs presented a decrease in tensile strength and elastic modulus, but increased elongation. It was observed that the films that contain AgNPs presented superior antioxidant activity compared to the other films, besides antimicrobial activity against the tested microorganisms.

Characterization of antioxidant methylcellulose film incorporated with α-tocopherol nanocapsules.

Biodegradable and antioxidant films based on methylcellulose (MC) and α-tocopherol nanocapsule suspension (NCs) were developed. MC and NCs films were prepared by a casting method in three different proportions. The mechanical, wettability, colour, light transmission, antioxidant and release characteristics of the films were studied. The addition of NCs to MC films decreased the tensile strength (TS) and the elastic modulus (EM) (p<0.05) but increased the percentage elongation at break (%E) and thickness (p<0.05). NCs films showed a higher hydrophobicity when compared to that of film control. Lightness and yellowish color were intensified in the NCs films which, in their turn, demonstrated high antioxidant activity and excellent barrier properties against UV and visible light. A burst and prolonged release of α-tocopherol to food simulant was also reported.

Extração de β-glucanas de cevada e caracterização parcial do amido residual / Extraction of barley β-glucans and partial characterization of residual starch

O objetivo do trabalho foi avaliar os parâmetros da extração de β-glucanas de cevada e caracterizar parcialmente o amido residual da extração. Foi desenvolvida metodologia para extração de β-glucanas de cevada sem degradação do amido, avaliando as variáveis pH e temperatura de extração. O percentual de β-glucanas extraída variou de 44,21 a 53,38 por cento, sendo influenciado pela temperatura, e o de amido extraído variou de 65,98 por cento a 77,54 por cento, sendo influenciado pelo pH. O amido residual da extração de β-glucanas de cevada apresentou poder de inchamento e solubilidade de 8,54±0,29 por cento e 6,04±0,073 por cento, respectivamente. O amilograma de ARV desse amido apresentou viscosidade máxima de 164,67±1,30 RVU e quebra de viscosidade de 45,79±2,06 RVU. O espectro de infravermelho do amido residual é típico de amido de cevada nativo e semelhante ao de amidos isolados de milho, trigo e mandioca. De acordo com as micrografias eletrônicas de varredura da fração amido, foi possível visualizar uma mistura de grânulos grandes e lenticulares, com um diâmetro médio de 19,15µm e de granulos pequenos com forma esférica, de 4,78µm. As características demonstradas pelo amido residual da extração de β-glucanas de cevada sugerem sua viabilidade para utilização na indústria de alimentos.

The objective of the study was to evaluate the parameters of the extraction of barley´s β-glucans and partially characterize the residual starch after extraction. A method was developed for the extraction of barley β-glucans without damaging the residual starch, assessing the variables pH and extraction temperature. The percentage of β-glucans in the extracted fraction varied from 44,21 to 53,38 percent , being influenced by temperature and the extracted starch varied from 65,98 percent a 77,54 percent, being influenced by pH. The residual starch from barley's β-glucan extraction had a swelling power and solubility of 8.54±0.29 percent and 6.04±0.07 percent, respectively. The RVA´s amylograph for this starch showed a maximum viscosity of 164.67±1.30 RVU and breakdown viscosity of 45.79±2.06 RVU. The infrared spectrum of the residual starch was typical of native barley starch and similar to isolated starch from corn, wheat and cassava. According to the scanning electron micrographs fraction of starch, it was possible to see a mixture of large lenticular granules with an average diameter of 19.15µm and small spherically shaped ones, with 4.78µm. The characteristics showed by the residual starch from barley´s β-glucan extraction, suggest a possible application in the food industry.