Rapid visible–near infrared (Vis–NIR) spectroscopic detection and quantification of unripe banana flour adulteration with wheat flour

Abstract

Unripe banana flour is a premium nutritious product with a potential to curb degenerative diseases through resistant starch and gluten free traits, however, with scant techniques to monitor adulteration practices. The objective of the present study was to determine the efficacy of visible-near infrared spectroscopy (Vis-NIR) spectroscopy (Vis-NIRS) in the detection and quantification of unripe banana flour adulteration with wheat flour. To do this, simulated adulteration of a composite banana flour was performed with different levels of wheat flour, in intervals of 20 g kg -1 , ranging from 0 to 800 g kg -1 . Each level was acquired in duplicate giving a total of 82 samples. Vis-NIR spectral data was acquired using a portable F-750 spectrometer in the range 447-1005 nm. Spectral data was analysed chemometrically using principle components analysis and partial least squares regression (PLSR), with 41 samples used as a calibration set and 41 for validation. The first two principal components accounted for 95% of spectral data variation, revealing five distinct clusters related to 0 g kg -1 , 20-200 g kg -1 , 220-400 g kg -1 , 420-600 g kg -1 and 620-800 g kg -1 adulterated samples. The best PLSR model to predict wheat flour adulteration degrees in unripe banana flour was obtained using 2nd derivative Savitzky-Golay (19-point smoothing, 2nd order polynomial), showing the highest R c 2 (0.991); R p 2 (0.993); RPD (12.021) and the lowest RMSEC (2.226 g kg -1 ) and RMSEP (1.993 g kg -1 ) values. The obtained Vis-NIRS PLSR models therefore demonstrated the technology novelty in monitoring unripe banana flour quality by the processing industries and in retail markets during product verification. Keywords Rapid detection Á Unripe banana flour Á Nondestructive technology Á Chemometrics Á Principal component analysis (PCA) Á Partial least squares regression (PLSR)

The effect of maturity and tissue on the ability of mid infrared spectroscopy to predict the geographical origin of banana (Musa Cavendish)

“…Banana ( Musa Cavendish ) is one of the most widely consumed fruits globally on a daily basis, and is one of the most important foodstuffs in many regions (Emaga et al ., 2007; Ndlovu et al ., 2019; Sun et al ., 2020). Banana trees are grown in high abundance in most tropical and subtropical regions which are primarily commercialised for export (Emaga et al ., 2007; Ndlovu et al ., 2019; Sun et al ., 2020).…”

“…The peel is rich in starch, total dietary fibre, proteins, lipids, amino acids and potassium (Emaga et al ., 2007; Ndlovu et al ., 2019; Sun et al ., 2020). Bioactive compounds extracted from banana have also been shown to possess antibacterial, antioxidant and antihyperglycemic properties (Emaga et al ., 2007; Qamar & Shaikh, 2018; Ndlovu et al ., 2019; Sun et al ., 2020). Banana pulp contains mostly starch, amylose and total fibre, as well as some proteins and lipids (Lehmann et al ., 2002).…”

“…Banana pulp contains mostly starch, amylose and total fibre, as well as some proteins and lipids (Lehmann et al ., 2002). In addition to providing the above‐mentioned multifaceted nutritional values and mineral elements, the beneficial roles of banana pulp also included the reduction of acute injuries, and protecting the gastric mucosa by enhancing its phospholipid layer from banana pectins (Dunji et al ., 1993; Emaga et al ., 2007; Ndlovu et al ., 2019; Sun et al ., 2020).…”

“…Despite the high nutritional and medicinal value of banana, optimal ripening stages of the fruit are necessary because the nutritional content and taste could be affected by different growth stages/maturity (Yang et al ., 2000; Emaga et al ., 2007; Ndlovu et al ., 2019; Sun et al ., 2020). Cavendish bananas are harvested at early mature stage presented in green colour and may be transported and stored for over a month under cooled conditions.…”

“…animal and plant tissues) with minimal preparation or processing of the sample (Huang et al ., 2016, 2020; Westworth et al ., 2019). Infrared spectroscopy combined with chemometrics analysis has been reported by several authors to be a reliable, rapid, and low cost method to evaluate the composition and provenance in a wide range of food products (Karoui et al ., 2010; Ellis et al ., 2015; Kamal & Karoui, 2015; McGrath et al ., 2018; Ndlovu et al ., 2019). The last 10 years have seen an increase in the number of reports on the use of vibrational spectroscopy techniques, including MIR, to target authenticity, fraud, regionality and traceability issues in a wide range of food matrices (Karoui et al ., 2010; Ellis et al ., 2015; Kamal & Karoui, 2015; McGrath et al ., 2018).…”