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Industry Resources

CDFA Regulations

Citrus Maturity Tables

Using the Tables



 In the 1980s, studies that were conducted using sensory panels in California, Texas, Nevada and New York indicated that consumers preferred oranges above the 8:1 ratio and that raising the ratio might lead to increased purchasing (Ivans and Feree, 1987; Pehrson and Ivans, 1988). Even though SSC/TA is currently used to determine the minimum standard in California, it has been recognized that this measurement does not always correlate well with the perception of sweetness or tartness in the fruit (Jordan et al., 2001). (Jordan et al., 2001) recognizing that sugar and acid have the opposite effect on flavor and that the tongue is more sensitive to acidity, proposed subtracting TA from SSC after multiplying TA by a constant that differs by fruit type. This measurement index given the name BrimA, was found to be more closely related to flavor than SSC/TA.


In 2003, after several years of increasing competition in the market place, declining navel revenues, and at the direction of its board of directors, Citrus Mutual asked the California Citrus Research Board to fund research to determine how the industry could increase consumer acceptance of navel oranges early in the season. The research was conducted over three seasons, beginning in 2003 and ending in 2006. The results from this extensive study indicate that the current California maturity standard of SSC/TA for oranges does not correlate with flavor well when the fruit have low acidity and that BrimA is a superior predictor of flavor under these circumstances. Although low-acidity fruit is primarily a feature of the late season when the maturity standard is not in use, the navel orange industry in California would be better served by using BrimA as a maturity standard rather than the current standard SSC/TA in order to lessen the possibility of low-acid, poor-tasting fruit entering the marketplace (D. Obenland et al./Postharvest Biology and Technology 52 (2009) 156-163).

Prompted by the results of the Citrus Research Board funded project Citrus Mutual in 2008 was awarded a Specialty Crop Block Grant to conduct a consumer study to see if an adjustment in the current minimum maturity standard would potentially increase consumption of California navel oranges by assuring consumers a better tasting piece of fruit. This was accomplished by determining if an alternative method for calculating orange maturity, BrimA (SSC-4*TA)), was consistently a better indicator of flavor than the current sugar to acid standard. The study concluded BrimA was superior to SSC/TA in predicting overall opinion, percent unacceptable fruit, purchase intent and purchase frequency.

Revising the maturity regulations for navel oranges from the SSC/TA to the California Standard [SSC-(4*TA)*16.5], derived from BrimA, will not involve any change in methodology or regulatory inspection procedures. The test using mL of sodium hydroxide and brix are exactly the same for determining the California Standard score as for determining the SSC/TA. The difference is the formula for calculating the result. Tables for the California Standard, similar to the ratio tables currently in use by the county agricultural inspectors have been developed. These tables were used by counties this past season to record both the ratio and the California Standard score. The comparative scores were provided to the scientist for analysis to measure the impact of the California Standard on the navel harvest. This analysis indicated that adopting the California Standard would in some cases alter specific locations where harvesting began, but would not have altered when the navel harvest started or the volume of fruit available to meet consumer demand at the beginning of the season.

Adopting the California Standard will increase the probability that the consumer will have a positive eating experience when they purchase a navel orange. The data from the consumer studies indicated that oranges selected using the California Standard solicited a minimal response of Aliked slightly@ 48% of the time while oranges selected using the ratio method solicited a similar response 14% of the time; representing a 38% higher probability that the consumer would have positive response. When consumers in the studies had a positive eating experience 66% said they would purchase more frequently, 59% would purchase more than usual, and 0% said they would wait to purchase. On the other hand when consumers in the studies had a negative eating experience, 37% said they would purchase less frequently, 43% would purchase fewer than usual, and 43% said they would wait to purchase again.

In 2009-2010 navel growers experienced one of the most successful season in their history. Exceptionally high quality, good tasting navel orange entered the market from the first harvest. The fruit ate well from the first week of the season, there was good customer acceptance and increased sales. The total crop in 2009-2010 was 6 million cartons smaller than the 2007-2008 crop, yet total fresh cartons shipped exceeded the larger 2007-2008 crop season by 8.5%. Further supporting that a positive consumer experience increases consumption is the report published in the 2011 Fresh Trends. According to this report oranges gained in popularity in 2010, climbing from the No. 7 spot to the No. 5 spot as most purchased fruit.