Proteomic potential of East African Highland Bananas (EAHBs) for banana juice extraction: comparison between juice-producing and cooking cultivars

ABSTRACT

This study investigated the proteomic difference between juice-producing and cooking EAHBs to clarify the role of protein in the production of banana juice. A comparative study was carried out to determine protein content, molecular weight distributions, and amino acid profile of the pulps of ten different (five juice-producing and five cooking) banana cultivars. There was low variability in crude protein content of banana cultivars, the level fell within the range of 0.80 g/100 g to 1.02 g/100 g. SDS-PAGE results visualised that the cultivars had similar molecular weights, ranging between 10 kDa and 76 kDa. The HPLC analysis showed that the relative compositions of amino acids differed significantly (p ≤ .05) within and between juice-producing and cooking cultivars. Both banana cultivars had a significantly higher amount of glutamic and aspartic acids, but significantly lower concentrations of tyrosine, methionine. The results suggest that protein content, molecular weight, and amino acid composition of banana cultivars are not the major factors in determining a banana’s ability to release juice.

RESUMEN

Este estudio investigó la diferencia proteómica entre los EAHB productores de jugo y los EAHB para cocinar, con el fin de esclarecer la función de la proteína en la producción de jugo de plátano. En este sentido, se llevó a cabo un estudio comparativo para determinar el contenido proteico, la distribución del peso molecular y el perfil de aminoácidos de las pulpas de 10 cultivares de plátano diferentes (cinco productores de jugo y cinco para cocinar). Dicho estudio permitió constatar la baja variabilidad del contenido de proteína bruta entre los distintos cultivares de plátano, toda vez que su nivel se situó en el rango de 0.80 g/100 g a 1.02 g/100 g. Los resultados de SDS-PAGE permitieron visualizar que los distintos tipos de cultivares poseen pesos moleculares similares, entre 10 kDa y 76 kDa. El análisis de HPLC dio cuenta de que las composiciones relativas de los aminoácidos difieren significativamente (p ≤ .05) dentro y entre los cultivares productores de jugo y para cocinar. Ambos tipos de cultivares de plátano poseen una cantidad significativamente mayor de ácidos glutámico y aspártico, pero concentraciones significativamente menores de tirosina y metionina. Por lo que, los resultados sugieren que el contenido de proteínas, el peso molecular y la composición de aminoácidos de los cultivares de plátano no son los principales factores que determinan la capacidad del plátano para liberar jugo.

KEYWORDS:

• East Africa Highland Bananas
• proteins
• juice release
• amino acids

PALABRAS CLAVE:

• Plátanos de las Tierras Altas de África Oriental
• proteínas
• liberación de jugos
• aminoácidos

Acknowledgments

The authors are grateful for the financial support from the Swedish Government Cooperation Agency (SIDA).

Disclosure statement

No potential conflict of interest was reported by the author(s).

Supplementary material

Supplemental data for this article can be accessed on the publisher’s website.

Additional information

Funding

This work was supported by a grant from the Swedish Government Cooperation Agency (SIDA), [Grant number DNR. ISP 2015/30:03], within the programme of sustainable agricultural productivity, processing, and value chain for enhancing food security in Tanzania.