Physical and chemical changes during ripening of blackberry fruits

Abstract

Blackberry (Rubus L.) is a naturally growing fruit in Anatolia. Consumption of fresh and frozen blackberries has increased in the past few years in Turkey. The aim of this study is to analyze blackberry at three levels of ripeness taking into account some physical and chemical properties (color, dry matter, soluble solids, total sugar, titratable acidity, pH, total phenolics, total anthocyanin, and minerals) in order to understand this behavior during the ripening process. Blackberry fruits were harvested at green, red and ripe (mature) stages. The determination of fruit maturity was based on fruit surface color. The dry matter, total phenolics and Hunter L, b values decreased but soluble solids, total sugar and total anthocyanins increased with maturity. In the early fruit ripening stages, pH decreased, titratable acidity and Hunter a value increased while in the later stages, pH increased, titratable acidity and Hunter a value decreased considerably. Analysis of variance revealed (P < 0.01) differences in these parameters based on ripeness stages. No remarkable changes in potassium, calcium, zinc and manganese concentrations occured during the development of fruits. Differences were observed for magnesium (P < 0.01), iron (P < 0.01) and copper (P < 0.05) during ripening of blackberry. Key words: Rubus L., color, anthocyanin, mineral matter MUDANÇAS FÍSICAS E QUÍMICAS DURANTE A MATURAÇÃO DE FRUTOS DE AMORA PRETARESUMO: Amora preta (blackberry, Rubus L.) é uma fruta que cresce naturalmente na península de Anatolia. O consumo de suas frutas frescas ou congeladas aumentou nos últimos anos na Turquia. Este estudo teve por objetivo analisar amoras pretas colhidas em três níveis de maturação, levando em conta propriedades físicas e químicas das frutas (cor, matéria seca, sólidos solúveis, açúcar total, acidez titulável, pH, fenóis totais, antocianina total e sais minerais) para melhor compreender o processo de maturação. As frutas foram colhidas nos estágios verde, vermelho e maduro. A determinação do estágio maduro foi baseada na cor da superfície das frutas. A materia seca, os fenóis totais e os valores de Hunter L, b diminuiram mas os sólidos solúveis, açúcares totais e total de antocianina decresceram em função do nível de maturação. Nos estágios iniciais de maturação, o pH decresceu, a acidez titulável e o valor a de Hunter aumentaram enquanto nos estágios posteriores o pH aumentou, a acidez titulável e o valor a de Hunter decresceram consideravelmente. A análise de variância revelou diferenças nestes parâmetros (P < 0,01), baseada nos estágios de maturação. Não houve mudanças marcantes nos conteúdos de potássio, calico e magnésio durante o desenvolvimento dos frutos. Diferenças foram obsevadas para magnésio (P < 0,01), ferro (P < 0,01) e cobre (P < 0,05) durante a maturação das amoras pretas.

Polyphenol content and antioxidant activity of maqui (Aristotelia chilensis Molina Stuntz) during fruit development and maturation in Central Chile

“…The highest increase was observed between the light red and purple stages. These changes are similar to other berry fruits (cranberry, pomegranate, blackberry, and red raspberry) where color development and sugar accumulation (SS) have been associated with the increase in anthocyanin pigment (Siriwoharn et al, 2004;Kulkarni and Aradhya, 2005;Celik et al, 2008;Tosun et al, 2008;Wang et al, 2009). The late stage of maturity showed the highest TA for both Paredones (8.82 g cy-3-glu kg -1 fw) and Rancagua (7.87 g cy-3-glu kg -1 fw), and this late maturity stage also had the highest SS.…”

“…The high TP in the first maturity stages was similar to other species such as strawberry, cranberry, pomegranate, teaberry (Gaultheria procumbens L.), mangosteen (Garcinia mangostana Linn. ), blueberry, and blackberry (Wang and Lin, 2000;Siriwoharn et al, 2004;Kulkarni and Aradhya, 2005;Celik et al, 2008;Rodarte Castrejón et al, 2008;Tosun et al, 2008;Pliszka et al, 2009;Pothitirat et al, 2009), which has an important ecological explanation. Plants with immature fruits -without viable seeds-have high phenol and proanthocyanidin contents that act as deterrent compounds to prevent their consumption by insects and herbivores, whereas ripe fruits have attractive colors (anthocyanins and other pigments) and a sweet taste to stimulate their consumption by herbivores and the consequent dispersion of seeds (Parr and Bolwell, 2000).…”

Towards Drylands Biorefineries: Valorisation of Forage Opuntia for the Production of Edible Coatings

“…Figure 4c shows the pH of the fruits measured during storage. At the beginning of the experiment, blackberries presented pH values (3.09 and 2.97 for the coated and uncoated fruits, respectively) comparable to those suggested by Tosun et al [36] as representative of mature blackberries (i.e., 3.14). During the storage period, the pH values of both groups increased to a similar extent (to 3.55 and 3.54 for the uncoated and coated fruits, respectively).…”

“…During the storage period, the pH values of both groups increased to a similar extent (to 3.55 and 3.54 for the uncoated and coated fruits, respectively). The increase in the pH is attributed to the natural process of fruit senescence; during this process, the content of organic acids declines, as they are either respired or converted to sugars [36]. The pH values obtained for both groups after the 10 days of storage were not significantly different (p ≤ 0.05).…”

Soluble solids, acidity, phenolic content and antioxidant capacity of fruits and berries cultivated in Serbia

“…For blackberry cultivars, the highest SSC was detected in 'Navaho', and the lowest in 'Black Satin'; the highest RI was also observed in 'Navaho', whereas 'Thornfree', 'Black Satin' and 'Čačanska Bestrna' had the lowest values with no significant differences among them. Large variability among cultivars regarding SSC has been previously observed [35]. Hence, Vrhovsek et al [27] reported that SSC were 9.3, 7.0, 7.5 and 10.6…”