Juan Yun

Inactivation of Salmonella enterica serovar Typhimurium and quality maintenance of cherry tomatoes treated with gaseous essential oils.

The antimicrobial activity of the essential oils (EOs) from cinnamon bark, oregano, mustard, and of their major components cinnamaldehyde, carvacrol, and allyl isothiocyanate (AIT) was evaluated as a gaseous treatment to reduce Salmonella enterica serovar Typhimurium in vitro and on tomatoes. In vitro tests showed that mustard EO and AIT had the greatest inhibition of Salmonella, followed by cinnamon EO and cinnamaldehyde, while oregano and carvacrol showed the least inhibition. Scanning electron microscopy images of S. Typhimurium on tomatoes suggest that the EOs and their major components damaged the bacteria, and the damage was more obvious after posttreatment storage at 10 °C for 4 and 7 d. Salmonella on inoculated tomatoes was reduced by more than 5 log colony forming units (CFU)/g by mustard EO and AIT, by 4.56 and 3.79 log CFU/g following cinnamon EO and cinnamaldehyde treatments, respectively, and 1.54 and 3.37 log CFU/g after oregano EO and carvacrol treatments, respectively. Mustard EO and AIT induced discoloration, softening, and loss of the vitamin C and lycopene during 21 d of storage at 10 °C, while treatment with cinnamon EO and cinnamaldehyde did not result in significant changes in tomato quality. Tomatoes treated with oregano EO had better quality than nontreated samples after storage. Therefore, treatment with cinnamon and oregano EO and their major components appeared to be feasible for inactivation of Salmonella on tomatoes and maintaining quality.

Effects of ascorbic acid and high oxygen modified atmosphere packaging during storage of fresh-cut eggplants

Ascorbic acid dip and high O2 modified atmosphere packaging were used to alleviate browning and quality loss of fresh-cut eggplants. Fresh-cut eggplants were dipped in water or 0.5% ascorbic acid solution for 2 min before being packed in polyethylene film bags filled with air or high O2. The physiochemical and sensorial attributes of cut eggplants were evaluated during 12 days for storage at 4 ℃. Results demonstrated that high O2 modified atmosphere packaging and ascorbic acid dip improved the preservation of fresh-cut eggplants compared with the control. High O2 showed an ability to reduce the browning and inhibit polyphenol oxidase and peroxidase activities. Higher total phenolic content and lower malondialdehyde content were also observed in ascorbic acid treated samples during storage. Moreover, the combination of ascorbic acid and high O2 was more effective than single treatments. The surface color was protected by ascorbic acid and high O2 packaging, and higher sensory scores were observed after 12 days of storage.

Response of antioxidant activity and sensory quality in fresh-cut pear as affected by high O2 active packaging in comparison with low O2 packaging

Effects of active modified atmosphere packaging (initial O2/CO2: 5/5; 30/5; and 80/0) and passive packaging [initial O2/CO2: 20.8/0 (air)] on the antioxidant capacity and sensory quality of fresh-cut ‘Yaoshan’ pear stored at 4 °C for 12 days were investigated. Samples stored in high O2 (30% and 80%) packages had higher phenolics and anthocyanin contents compared with those in passive and low O2 packages. After 12 days of storage, phenolics and anthocyanin contents of 80% O2 samples were 2.5 and 12 times, respectively, higher than those in the passive package and 3 and 2 times higher than those in low O2 package. High O2 modified atmosphere packaging was effective in keeping free radical scavenging capacity as measured by the DPPH assay. The sensory evaluation indicated that surface color of cut fruits were stable for at least 12 days in the high O2 modified atmosphere packaging. The results suggested that high O2 modified atmosphere packaging could be used to inhibit browning and prolong the shelf life of fresh-cut ‘Yaoshan’ pears in spite of more than 50% loss in vitamin C content.

Characteristics and Release Behavior of Sodium Alginate Microencapsulation Containing Cinnamon Oil

Microencapsulation technology is widely used in many industries recently because the stability of core material can be improved and the release characteristics can be modified. In this investigation, cinnamon oil was microencapsulated by simple coacervation. The size distribution is narrow and the mean diameter is 53.79 μm. The surface morphology of the resultant microcapsules was also characterized scanning electron microscopy (SEM). The results showed that the rates of cinnamon oil released from microencapsulation were not only affected by relative humidity in the microenvironment around microencapsulated powder, but also affected by the temperature.

Evaluation of Nano-packing on the Shelf Life of Fresh-Cut Lotus Root (NelumbonuciferaGaerth)

The effect of nanocomposite low-density polyethylene (LDPE) films containing ZnO and silver nanoparticles on preservation of lotus root (NelumbonuciferaGaerth) store at 4 °C for 12 days was investigated. The nano-packing not only suppressed the growth of aerobic bacteria (<4 log cfu g−1), but also inhibited the increasing of yeast and molds, the maximum growth of which reached only 3.3 log cfu g−1 in the nano-packing while 5.6 log cfu g−1 in control. The least degradation of ascorbic acid (AA) (39.2 mg/100 g) and browning rate (0.56) were observed in package containing nano-ZnO and nanosilver particles. Fruit decay and MDA content were efficiently reduced in nano-packing samples. The results reveal that nano-ZnO and nanosilver coated film as an alternative non-thermal technology can extend the shelf life of fresh-cut lotus root up to 9 days.

Antimicrobial Activity of Microencapsulated Cinnamon Oil and Its Application on Cherry Tomato

In this investigation, antibacterial property of microencapsulated cinnamon oil was investigated. Microencapsulated cinnamon oil was prepared by simple coacervation. Microencapsulated cinnamon oil exhibited good antimicrobial activities.Moreover, the effect of microencapsulated cinnamon oil on the quality of cherry tomato was investigated. Result showed microencapsulated cinnamon oil could reduced fruit decay and keep the quality of cherry tomato.

The Effect of Formulation Variables on the Encapsulation Efficiency and SO2-Release Behavior of Microparticles Containing Sulphite

The water-soluble sulphite was encapsulated using ethylcellulose phase separation. The effect of different process factors in the phase separation process on the encapsulation efficiency and the release profile of SO2 from the microparticles were evaluated. The results showed that the SO2 release from the microparticles containing sulphite was affected by the relative humidity in the microenvironment.

Effects of different temperature and humidity on the quality of Chinese yam (Rhizoma dioscoreae) during storage

Chinese yam is easily mouldy and decayed during the process of storage and transportation because of high water content in the tissue of tubers associated with injures during or after harvesting which makes them vulnerable to micro-organisms disease. The temperature and the humidity as vital factors in the preservation were studied. Graded temperature and humidity were adopted to observe the effects on the preservation quality of Chinese yams. The results showed that room temperature (18∼23 °C) combined with low humidity (RH, relative humidity 15%∼20%) had good effects on maintaining the quality of Chinese yams. On day 80, indexes including PPO, MDA, TSS and firmness of yams stored at room temperature were 5.64 U/g-FW, 0.74 μ mol/L, 1.83%, 10.80×106 N/m2, and those of samples stored in RH 15%∼20% were 2.72 U/g-FW, 0.49 μ mol/L, 1.81%, 10.59×106 N/m2, respectively, which were better than other storage condition.

Effect of Different Maceration Levels on the Antioxidant and Bioavailability of Wine from Vitis vinifera Cv. Muscat Hamburg

The paper studied the effect of different maceration levels on the antioxidant and bioavailability of wine from vitis vinifera cv. Muscat Hamburg in China. The bioavailability of phenolic fraction was assayed for Folin-Ciocalteu Reaction (FCR) reducing capacity, and methanol content was determined with Gas Chromatography. All maceration treatments raised wine polyphenolic content and antioxidant while increased the methanol, too. Evaluated by an in vitro digestion process, the bioavailability of polyphenolic compounds and methanol in wine showed that the FCR value of the full-maceration samples was the highest (31.56%), the methanol content of the samples was higher than that of other three groups (29.60%), and the availability was up to its maximum absorptivity (53.07%). It suggests that the Muscat red wine may represent higher quality and bioavailability after extended maceration.

SO2-Release Performances of Sulphite Microparticles under Different Relative Humidity: SO2-Release Performance

In this investigation, the water-soluble sulphite was encapsulated using ethylcellulose phase separation and then ethylcellulose microcapsules were used as core material to prepare dual coated microparticles using melting scattered condensation method. Morphology of microencapsulation was observed by scanning electron microscopy (SEM). Release profiles of SO2 from sulphite microparticles were also studied. The results showed that the rates of SO2 released from microparticles were not only affected by varying the type, but also by the relative humidity in the microenvironment around microencapsulated powder, which was greatly accelerated with increasing the relative humidity.