Using dry matter as a measure of maturity in fresh produce

Fruit is transported over long distances nationally and internationally to cater to a broad market. This makes it necessary to harvest fruits as soon as they are mature to increase the time available for their transport and storage, thus improving profits. Determining fruit maturity is, however, not simple. There are several qualitative ways to fix the best harvest time for fruits and vegetables; however, in many cases, especially climacteric fruits, it is best to use precise instruments. Understanding what the instruments measure, which in many cases is dry matter, can help in their use. What is dry matter?The solid component of any fruit, leaf, stem, or roots without the water component is called dry matter (DM). Dry matter from fruit is the result of the accumulation of carbohydrates, starches, sugars, oils, proteins, antioxidants, vitamins, minerals, fiber, lipids, volatile compounds, etc., along with a build-up of structural carbohydrates like fiber and skin. Dry matter as a measure of maturity and qualityDry matter changes during the different stages of fruit development, and this correlation makes it a good indicator of maturity in both climacteric and non-climacteric fruits. Moreover, the dry matter accumulated by plants depends not only on its genotype, but also the field conditions in which the plants grow and the cultivation methods used. This increases dry matter’s reliability as a measure of maturity and fruit quality. Non-climacteric fruits: Besides dry matter, color, size, and firmness are additional criteria that can be used to judge the correct time to harvest non-climacteric fruits. Climacteric fruits: In climacteric fruits, dry matter is fast replacing traditional measures of fruit maturity such as firmness, as there are few external indicators. While dry matter is a good indicator, for climacteric fruits that ripen post-harvest, there can be some exceptions. In apples, firmness and starch index changed with late maturity stages more than dry matter did, making them better measuring tools than dry matter. Indirect RelevanceIn avocado, dry matter is not the indicator of maturity. It is the oil content of the fruit that correlates with the maturing process and is found to increase as the fruit matures. However, measuring the oil content can be difficult or expensive. On the other hand, it has been found that water content in avocados decreases as oil content increases. Thus, dry matter in avocados correlates with oil content, and so, by measuring dry matter, it is possible to judge if the fruit is mature enough to be plucked. A minimum oil content of 11.2% is optimal to guarantee maturity in avocados; this concentration of oil content can correspond to 22% to 26% of dry matter in different varieties of avocados. The F-751 is a portable NIR analyzer designed by FELIX INSTRUMENTS to specifically evaluate the maturity of avocados based on their dry matter content. How to measure dry matterIn the laboratory, dry matter is measured by drying fresh fruit in an oven or dehydrator. Dry matter is the ratio of dry weight to the fresh weight (or weight of the fruit before drying). In the field, handheld sensory instruments rely on near infrared (NIR) spectroscopy. This is a non-destructive way to estimate dry matter levels and does not affect the fruit tested. The F-750 Produce Quality Meter can be used on several fruit species. The readings are precise, and the instrument is also useful for scientific studies on fruit quality and maturity. Improving food productionHarvesting fruit at different stages of maturity has an impact on the ultimate taste. Growers need to know the correct time to harvest fruit so that the quality of the fruit is not affected. Dry matter estimation tools are one of the modern applications designed and manufactured to make the production of fruits and vegetables easier and quality control more consistent.