Impact of salicylic acid and calcium chloride on quality attributes of peach stored at refrigeration temperature.

Salicylic acid (SA) in different concentration were used to assess its individual effect as well as combined impact with 3% calcium chloride (CaCl2) on Swat No. 8 variety of peach stored at refrigerated temperature (6 ± 2 °C) for 21 days. Interestingly, the results revealed that applying 2 mmol L-1 SA with 3% CaCl2 maintained maximum nutritional value and least decay percent (44.1%) as compared to other treatments during storage. Moreover, this combination also exhibited significant weight loss and chilling injury at 6 ± 2 °C whereas increased levels of total phenolic, flavonoids, tannin, alkaloid, ascorbic acid, and antioxidant activity were observed as compared to other treatments. The combination treatment (2 mmol L-1 SA with 3% CaCl2) maintained other sensory attributes of peach fruit during refrigerated storage, therefore, its commercial use was recommended to store peach fruit for up to three weeks without any significant nutritional and physical loss.

Application of starch nanoparticles as host materials for encapsulation of curcumin: Effect of citric acid modification.

To encapsulate curcumin, absolute ethanolic curcumin solution with various content (300-1200 µg) was added to aqueous dispersion of citric acid-modified starch nanoparticles (M.SNPs) with various contents (0.5-2.5%), and then ethanol of the mixture was evaporated by nitrogen gas purge for 40 min (ethanol content decreased to 1%). SNPs (100 mg) could encapsulate 75.7 µg of curcumin in matrices of the composite, while 100 mg of M.SNPs could encapsulate 144.9 µg of curcumin. The XRD results revealed that curcumin was amorphously encapsulated in the composite, and hydrogen bond formation between M.SNPs and curcumin was one of the major driving forces for encapsulation as suggested by FT-IR. The composites had a spherical shape and mean particle size of the composites was increased from 136.3 to 255.3 nm with higher curcumin content in the matrices of composites. UV, pH, and thermal stability of curcumin significantly enhanced by the encapsulation, which was further increased when using M.SNPs and/or higher content of host materials. For the release of curcumin in simulated intestinal fluid digestion, release mechanism explained by Korsmeyer-Peppas model. For M.SNPs, k value was decreased from 13.097 to 2.938 as addition level of host material increased from 0.5 to 2.5%.

Fabrication of citric acid-modified starch nanoparticles to improve their thermal stability and hydrophobicity.

Starch nanoparticles (SNPs) were reacted at 130 °C for 1.5 h in the presence of citric acid (30 %) to enhance their thermal stability and hydrophobicity. Citric acid content in SNP was controlled by washing with different concentrations of ethanol (95 %, 70 % and 60 %) for 2, 5 and 10 min and then subjected to heat treatment at 130 °C. After the modification, the peak at 1732 cm-1 representing ester bond was observed via FT-IR, and the intensity of the peak was decreased with a lower ethanol content in washing medium. For the 60 % ethanol condition, the granular structure was promptly fragmented into particles less than 50 nm in the aqueous solution. The modification enhanced the thermal stability and hydrophobicity of the SNPs. The modified SNPs was used as a nano-vehicle wall material for encapsulating beta-carotene as a model hydrophobic material. Approximately 80 % beta-carotene was encapsulated in the modified SNPs.

Controlled fragmentation of starch into nanoparticles using a dry heating treatment under mildly acidic conditions.

Normal corn starch was treated with acidic ethanol solution with various concentrations of ethanol (0, 10, 30, 50 and 95%) and acid (0.0026, 0.0053 and 0.0079M) and then subjected to a dry heating treatment for 1, 2 and 4h at 130°C to prepare starch nanoparticles. Size of nanoparticles was determined using DLS (dynamic light scattering). FT-IR (Fourier-transform infrared spectroscopy), XRD (X-ray diffraction) and TEM (transmission electron microscopy) were used to determine the structure and morphology of starch nanoparticles. As the ethanol concentration decreased, the starch granule readily fragmented into smaller particles when simply dispersed in water, and this was possibly by the preferential hydrolysis of the starch chains in the amorphous region. A higher ethanol concentration (50 and 95%) did not produce homogenous nanoparticles, however 30% ethanol concentration produced uniform nanoparticles with a mean diameter of 46.4nm. The treatment condition (30% ethanol) partially broke the long-range crystalline order but left the short range order of the spherical nanoparticles intact. However, lower ethanol (<30%) concentrations induced severe damages in the both crystalline structures (long and short range) of starch granule.

Evaluation of nisin-loaded chitosan-monomethyl fumaric acid nanoparticles as a direct food additive.

Nisin-loaded chitosan-monomethyl fumaric acid (CM-N) nanoparticles were evaluated as a novel, direct food additive. Chitosan (CS) was modified with monomethyl fumaric acid (MFA) in the presence of 1-ethyl-3-(3-dimethylaminopropyl) carbodiimide (EDC). CS-loaded nisin (CS-N) and CM-N nanoparticles were produced through ionic interactions between the positive amino group of CS and CS-MFA and negative tripolyphosphate ions. The resultant materials were characterized by TNBS assay, X-ray diffraction, Fourier-transform infrared spectroscopy, scanning electron microscopy, thermogravimetric analysis, and zeta potential analysis. CS-MFA was successfully synthesized with 8.38 ±â€¯0.02% substitution of the amino groups, as confirmed by TNBS assay. The percentage yield of CS-N and CM-N nanoparticles was 81.64 and 76.83% and nisin encapsulation efficiency was 71.48 ±â€¯0.48 and 60.32 ±â€¯0.63%, respectively. The average particle size of CS-N and CM-N nanoparticles was 134.3 and 207.9 nm, while the zeta potential of CS-N and CM-N nanoparticles was +39.4 mV and +31.5 mV, respectively. Upon antibacterial activity against foodborne pathogens, CM-N significantly reduced bacterial counts compared to the other tested samples in orange juice after 48 h of incubation. Based on the preliminarily results, CM-N nanoparticles have shown impressive properties and can be used in the food industry as carriers and direct antimicrobial agents.