Commercial quality of ‘little gem’ lettuce hearts

Abstract

Demand for high-quality lettuce by discerning wholesalers, retailers, and consumers has increased in recent years. However, few studies have characterised the range of commercial quality parameters of ‘Little Gem’ lettuce. Therefore, we aimed to characterise the commercial quality of ‘Little Gem’ (Lactuca sativa L.) lettuce hearts and their application by comparing two annual production and marketing programs for fresh whole lettuces. Over one year of cultivation, the external appearance (weight, colour, length, diameter, slenderness, firmness, and compactness of the head), internal appearance (number and density of leaves, stem dimensions, and white-yellow inner core), and internal quality parameters (total soluble solids, dry matter content, maturity index, and bitter sesquiterpenic lactone content) were evaluated. The results revealed that by evaluating both the external and internal appearance, along with the internal quality parameters, we could characterise and compare two annual varietal programs of ‘Little Gem’ lettuce. Moreover, the lettuces from an Aspirant varietal program intended to replace the current commercial program achieved results more acceptable to consumers than lettuces from retail supermarket chains (weight > 95 g, firmness > 3.5, light green colour, well-proportioned shape, and slender). In addition, the significant interaction between the varietal programs and the month of study suggests the need to adapt the choice of variety to seasonal conditions. Collectively, these findings highlight the impacts of both genetic factors and growing conditions throughout the year on the quality of ‘Little Gem’ lettuce hearts, as perceived by consumers.