Table 6. 

 1998. 



Some storage characteristics of Mutsu and Shizuka apples harvested October 2, 



Storage through: 



Superficial scald (%) 



Mutsu Shizuka 



Firmness^ 



Desirability^^ 



Mutsu Shizuka 



Mutsu Shizuka 



12/15/98 (32Fau-) 25 3.0 1.8 3.3 2.5 



2/1/99 (32F air) 83 1.5 1.5 2.0 2.2 



2/8/99 (CA) 4 2.3 2.5 3.5 3.0 



^ Firmness and desirability are both rated on a scale of 1 to 5, with l=poor, 2=fair, 



3=acceptable, 4=very good, 5=outstanding. 

 '' Desirability includes firmness, flavor, acidity, crispness, and appearance conponents. 



2' 



to 



"soft" room; 

 38°F, 2.8%0 

 varying CO^ 

 5%. Table 6 

 shows how dra- 

 matically CA 

 storage im- 

 proved some 

 poststorage 

 characteristics 

 of Mutsu and 

 Shizuka. The 

 reduction in su- 

 perficial scald 

 development on 

 Mutsu is of par- 

 ticular interest. 



from storage actually happened on February 1, 1999. 

 Assessment of poststorage fruit disorders was 

 made following a week at room temperature, and 

 results of the assessments are shown in Table 5. 

 Because findings were similar for fruit removed from 

 cold storage in December and January, results have 

 been combined. Table 5 shows that poststorage 

 disorders did not occur with consistency. Senescent 

 breakdown was a problem in Mutsu following the 

 1999-2000 storage season. However, no significant 

 senescent breakdown was found in either variety 

 following storage and a week at room temperature the 

 following two years, and very little developed in the 

 1998-99 storage season. There was a substantial 

 amount of superficial scald following storage in 1998- 

 99, but much less in the following years. Mutsu was 

 more scald susceptible than was Shizuka. Neither 

 scald nor breakdown could be attributed to time of 

 harvest, although the year with the most scald (1998) 

 was one in which there was no late harvest, and scald 

 is most likely to develop on early harvested fruit. 

 Other disorders assessed were bitter pit and decay, 

 neither of which occurred with enough frequency to 

 analyze. We did note moderate skin greasiness on 

 Shizuka from the late harvests of 2000 and 2001 after 

 they had spent a week at room temperature in January. 



Controlled Atmosphere (CA) Storage 



Fruit were stored in CA as well as in refrigerated 

 air during the 1998-99 storage season. The CA was a 



Conclusions 



Based on the 1998-99 storage season's data, CA 

 appears to be necessary for both Mutsu and Shizuka if 

 they are to be stored beyond mid-December. Even in 

 mid-December the Shizuka did not emerge from air 

 storage in good condition in 1998, although they did 

 better in subsequent years. The Shizuka had probably 

 reached the limit of their quality CA life in 1998-99 

 when they were tested in February, while the Mutsu 

 could have gone longer in CA and emerged in 

 acceptable condition. The quality difference between 

 air and CA storage was dramatic for both cultivars. 



Mutsu retains good quality in storage longer than 

 Shizuka. The areas in which Shizuka fared better were 

 appearance (3.1 vs 2.7 on the I to 5 scale) and scald 

 resistance. Shizuka does tend to be a smaller apple 

 which could be an advantage, since both cultivars can 

 be very large. Where blister spot is not a limiting 

 factor, Mutsu would be the more highly recommended 

 cultivar in a marginal storage situation. Shizuka could 

 be an acceptable substitute if the fruit were marketed 

 primarily in the fall or stored in CA. It is a more 

 attractive fruit than Mutsu, and for the September 

 market, Shizuka has the advantage of ripening slightly 

 earlier. If Shizuka is to be stored longer than mid- 

 December, it should be placed in CA. 



Either Mutsu or Shizuka can be an acceptable 

 large green/yellow apple for the autumn market if 

 handled properly after harvest. 



it "k it it it 



Fruit Notes, Volume 67, Summer, 2002 



