Zhensan Li’s scientific contributions

We formerly reported a special lowoxygen CA combination (2 %O2 + 7. 5 %CO2) , which can control superficial scald of apples for a longer period after 4 months of treatment . Now , a further experiment of Starkrimson apples was conducted to study the effects of delayed and shortened treatment . The results showed that the scald incidence of apples of control (0 ℃, air) and conventional CA treatment (0 ℃, 3 %O2 + 3 %CO2) were 25. 6 % and 1. 02 % respectively , and their flesh firmness were 5. 79 and 6. 52 kg/ cm2 respectively after 123 days of storage. The apples of special CA treatment (10 ℃, 2 %O2 + 7. 5 %CO2) was scald2free after 123 days of storage , its flesh firmness (6. 63 kg/ cm2) was the same as that of conventional CA treatment and significantly higher than that of control . The apples of delayed treatment developed scald (6. 67 %) after 15 days of storage at 10 ℃in air and 108 days of special CA treatment , its flesh firmness (4. 8 kg/ cm2) was significantly lower than those of control and conventional CA treatment . These results indicted that it is necessary to treat apples with special CA combination on time. The scald incidence of apples of control , conventional CA treatment and special CA treatment were 46. 9 % , 36. 4 % and 0 respectively after 123 days of storage plus another 58 days of cold storage in air , their flesh firmness were 5. 28 , 5. 21 and 4. 5 kg/ cm2 respectively. The apples of special CA treatment was also scald-free after 96 days of storage plus another 50 days of cold storage in air , its flesh firmness was 4. 67 kg/ cm2 . Based on the consideration of both scald incidence and flesh firmness , it is possible to change the duration of special CA treatment from 4 months to 3. 3 months if we want to store apples for about 5 months. The formations of α-farnesene and conjugated trienes in the peels of apple fruits were significantly inhibited by special CA treatment during CA storage.

Based on a successful experiment of a special low oxygen CA combination storage, 2394kg apples were treated in a chamber enclosed by 0.12mm thickness of PE film, gas composition was adjusted by nitrigen gas during the first 4 months; then the PE chamber was sealed and the apples were in MA storage during next 2 months. The results indicted that the oxygen level in the PE chamber could be adjusted to 2% low oxygen level and carbon dioxide could be maintained in the ideal range during the first 4 months. Then, when gas composition was not adjusted, it could still be mainrained at 6.6%-10.6% O2 and 8.6-9% CO2 during next 2 months. After 6 months of storage, the treated apples kept good fresh appearance, low scald incidence (1.7%) , low decay rate, high flesh firmness and high chlorophyll level. Furthermore, the apple scald incidence was only 5.9% after another 51 days of cold storage.

The physiological basis of post - storage effects of low - oxygen CA treatment which can control superficial scald of apples for a longer period was studied, using Starkrimson apple as experimental material. The results showed that the α- farnesene and conjugated trienes contents of special CA - treated apples were significantly low ,its fruit firmness , soluble solids and peel chlorophyll levels were almost the same as those of standard CA ,equal to or higher than those of cold storage in air after 4 months. When special CA - treated apples were stored in cold air ,α- farnesene and conjugated trienes contents of special CA - treated apples were high ,but apples were still scald - free during 2 months of post - storage periods. The formations of α- farnesene and conjugated trienes were significantly inhibited by special CA treatment during CA storage and the accumulation peak of conjugated trienes was delayed to appear after a longer post - storage period ,this may be the reason why no scald fruit was observed among special CA - treated apples during a longer post - storage period.

The efficacy of low oxygen controlled atmosphere (CA) treatment combinations (2% O2 + 3, 7.5 or 12% CO2) in controlling superficial scald in apple cv. Meiguihong, a strain of Delicious, stored at 0 and 10°C, was investigated. Fruits stored at 2% O2 + 7.5% CO2 were firmer and had a higher chlorophyll content compared with those stored under control (0°C, air) conditions. However, the contents of α-farnesene and conjugated trienes of fruits stored under this CA treatment were lower than those stored under control conditions after 121 days. Thereafter, fruits stored at 10°C + 2% O2 + 7.5% CO2 were scald-free after storage in air at 20°C for 7 days or at 5-7°C for 122 days. Fruits stored at 0°C + 2% O2 + 7.5% CO2 were also scald-free after storage in air at 5-7°C for 30 days. The results indicate that suitable low oxygen CA treatment can control superficial scald of apples for a longer period after low oxygen CA storage.

A geomitric shape, which can be mathematically described by elliptical and linear equations, was proposed to represent pear fruit shapes. Then, a formula for estimation of pear fruit surface area was the equations mentioned above and a new method was established. This is a paper published in English.

THis paper presents the ideas and techniques for designing and realizing the interface and functions of the DPS-98 software, introduces functional features of the software, including good interface, easy data input, data checking and correcting, and results output with various methods.

The fruit respiration rate are usually measured in air under room temperature condition, it could not be used to represent the actual respiration rate of fruits under controlled atmosphere storage condition. Here we introduced a method for measuring respiration rate of fruits under controlled atmosphere storage condition. In this method, an infrared CO2 analyzer and a recorder were used to measure CO2 concentration change. At the beginning of measurement, the indicator CO2 concentration was recorded and adjusted to zero; then, the recorder was changed to a more sensitive range; some times later, the change of CO2 concentration was measured and calculated using an equation.

The storage effects of various CA treatments on Starkrimson apples at different temperatures were studied. The effect of treatment (3.5%O2+6%CO2) at 5℃was best after 182 days. The effect of treatment (2%O2+7.5%CO2) at 9℃was better after 126 days, no superficial scald among treated fruits was observed.

The storage effects of several CA treatments on White Winter Pearmain apples at 0℃ and 10℃ were studied.