*2.1. Fruit Quality*

According to Barrett et al. (2010) [28], in reference to fruits, the characteristics that impart a distinctive quality may be described by four di fferent attributes: color and appearance, flavor (taste and aroma), texture, and nutritional value. All these aspects are determined through the complex biological process of fruit development and ripening [29,30].

We next summarize the main quality aspects of Patagonian berries, such as color and appearance, flavor, and texture. Nutritional and functional value-related antecedents of berries will be addressed in the next sections.

#### 2.1.1. Color and Appearance

The precise definition of the developmental and ripening stages is necessary to determine the physicochemical and physiological parameters that contribute to the di fferent quality attributes of fruit at harvest. A representative fruit at the ripe stage for each species analyzed in this review is shown in Figure 1. In Chilean strawberry, four developmental fruit stages have been described (i.e., small green, C1; large green, C2; turning, C3; and ripe fruit, C4) [31]. The ripe fruit stage (at harvest) has shown a pink receptacle and red achenes that, in comparison with the ripe stage of *Fragaria* x *ananassa* ('Aromas') fruit, can be 200-fold less red (comparison of the a\* color parameter) [32,33]. Regarding the fruit weight of *F. chiloensis* fruit, it is nearly half of that present in modern commercial strawberry varieties (such *F*. x *ananassa* 'Chandler') [31]. In maqui berry, five di fferent maturity stages have been described, starting from 21 days after fruit set in central Chile and named as green (I and II), light red, purple, and dark purple stages [34]. The berry weight per 100 fruits ranges from 10 g (green I stage) to 21 g (dark purple stage), with the highest increase in weight between the green II and light red stages.


**Table 1.** Main features of Patagonian fruits analyzed in the present review. Scientific and common names, botanic family, geographic distribution, traditional

**Figure 1.** Patagonian berries with healthy potential as a functional food on the basis of recent research data available. (**A**) *Aristotelia chilensis* (Mol.) Stuntz (maqui)\*; (**B**) *Ugni molinae* Turcz. (murta)\*; (**C**) *Berberis microphylla* G. Forst. (calafate)\*; (**D**) *Luma apiculata* (DC.) Burret (arrayan)\*\*; (**E**) *Fragaria chiloensis* (L.) Mill. (Chilean strawberry)\*\*. Photography credit to M. Teresa Eyzaguirre-Philippi (\*) and Carlos R. Figueroa (\*\*).

The shape of murta and arrayán fruit was reported as globular, with a major equatorial diameter [21,44]. As far as we know, the only report for arrayán fruit development was made by Fuentes et al. (2016) [21]. In that work, the authors classified the fruit development into four stages, mainly by fruit shape and skin color: small and thin green (La1), rounded turning (La2), rounded purple (La3), and black ripe (La4) berries, with a decrease in lightness (L\*), b\*, and chroma values of fruit skin from approximately 48 to 23 from La1 to La4. As expected, a constant increase in the fresh and dry weight was observed during fruit development, although a higher increment was noted between the La3 and La4 stage [21].

For calafate berry, Arena and Curvetto (2008) [45] described a typical double sigmoid curve for fruit growth, with a constant increase in both the fresh weight and the diameter from 14 to 84 days after full flowering, reaching a maximum of 420 mg and 9.6 mm, respectively.
