Application of FT-NIR technique in determination of honey quality.

Honey, valued for its nutritional and therapeutic properties, faces economically motivated adulteration with cheap sugar syrups, undermining consumer trust and regulatory compliance. This thesis evaluates Fourier Transform Near-Infrared (FT-NIR) spectroscopy as a rapid, non-destructive alternative to traditional methods for honey quality assessment.
The study analysed 52 Indian honey samples. Physicochemical parameters pH, moisture content, and total soluble solids (°Brix) were measured via standard methods (AOAC). High-Performance Liquid Chromatography (HPLC) provided reference values for fructose (15.26–69.60%), glucose (20.81–65.26%), sucrose (0–3.046%), maltose, and fructose-to-glucose (F/G) ratios (0.66–1.78). FT-NIR spectra (12,000–3,800 cm⁻¹) were acquired using a Bruker MPA II spectrometer on 25 overlapping samples, with partial least squares (PLS) models built against HPLC data.
Reference analysis showed 63.5% of samples met FSSAI sucrose limits (<5% w/w), but 36.5% exceeded moisture limits (>20% w/w), posing stability risks. Adulteration with barley malt syrup (0–30% v/v) was detectable by HPLC via rising maltose and oligosaccharide peaks.
The failure to quantify sucrose variability, resulting in a constant prediction of ~0.8% across an actual range of 0–3.046%, was attributed to the absence of sucrose and maltose reference data in the FT-NIR spectral library, which, combined with spectral overlap in the 9,000–7,000 cm⁻¹ region, prevented the model from resolving these components.
While FT-NIR enables fast, preparation-free screening, its quantitative accuracy for individual sugars lags behind HPLC. HPLC remains essential for regulatory honey authentication; FT-NIR suits preliminary high-throughput triage pending improved calibrations.