STEP Systems GmbH
STEP Systems Newsletter
June 2016

Fruit Quality Control

Why measure fruit maturity?

Fruit quality control
The criterion determining the harvest time between reaching maturity and ripeness is usually dependent on the product postharvest-life.

  • Fruits collected before they reach maturity, with few exceptions, do not ripe later and are therefore suitable for long-term storage
  • Fruits fully ripened on the plant, have the best eating quality, but cannot be stored long

Evaluation of the maturity index is important for the regulation of the postharvest handling and an efficient use of manpower and resources.

Maturity attributes include:

  • size and shape
  • color
  • density
  • sugar content
See different measuring instruments below or in our STEP Systems catalog.

Fruit quality testers

Sugar content:
is measured with a refractometer, by dropping the liquid probe on the prism of the instrument.
Analogue Refractometer
Analogue Refractometer
Item no.: 25010
Рефрактометр цифровой
Digital Refractometer
Item no.: 25020

Reference table (% Brix) for maturity determination
Quality Bad Medium Good Excellent
Potatoe 3 5 7 10
Apple 6 10 14 18
Onion 4 6 10 12
Carrot 4 8 14 18
Tomatoe 4 6 10 14
Honeydew melon 8 10 14 16
Water melon 8 12 16 18
Grape 8 12 18 22
Salad 4 6 8 10
Cherry 6 8 14 16
Pear 6 10 14 16
Orange 6 10 16 20
Fruit density:
Fruit penetrometer helps to determine the degree of maturity at harvest as well as fruit quality during storage.
Analogue Fruit Hardness Tester
Digital Fruit Hardness Tester
Reference table for fruit density at harvest
Fruit Cultivar Firmness
(kg / cm²)
Pear William´s / Guyot 6.5
Conference 5.5
Abate Fetel 5
Comice 4.5
Apple Staymanred 7.5
Stark Delicious 6
Golden Delicious / Granny Smith 5.5
Plum Calita 2.5
Golden Japan / Ozark Premier 3
Peach Creasthaven, Suncrest, Flavor Top, Red Haven 6
Fruit size:
is measured by calipers, depending on the fruit size.
Fruit callipers
Fruit callipers
different sizes
Universal calliper
Universal calliper
Item no.: 45020

    Around the world    

From 26 to 29 April 2016, STEP Systems took part in the Agrotech-Agropars exhibition in the city of Shiraz. Being the largest of the three leading agricultural fairs in Iran, Agrotech-Agropars is also a platform for the long-awaited establishment of relations with Iran.

At SIAM exhibition, which was held in late April, STEP Systems was represented by its partners in Morocco, the company Metagrhyd Sarl. SIAM is the largest agricultural fair in North Africa.
From 11 to 13 May 2016, Beijing hosted the 18th Hortiflorexpo, the biggest and most important fair for the horticultural industry in China. STEP Systems was presented at the joint stand of the German Federal Ministry of Food and Agriculture, with Harald Braungardt, CEO of STEP Systems, as the official representative of the Ministry.
Web page
Web page

STEP Systems GmbH
Duisburger Str. 44
90451 Nuremberg

Tel.: (49-911) 96 26 05 0
Fax: (49-911) 96 26 05 9
👉 Stay tuned for more useful information about our measurement technology
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