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Three simple near infrared (NIR) spectrometers, with differing dispersion elements (single equilateral prism, two equilateral prisms in series, and a ruled diffraction grating) were constructed to compare their relative performance for suitability for in-line fruit sorting. Performance in terms of resolution, spectral range, efficiency, and linearity across the spectral range was characterized using a HgAr discharge source. Further, a practical application was assessed by comparison of spectra of transmitted radiation from whole immature and mature limes (Citrus aurantifola) over the wavelength range 650-1050 nm. Light from a 100 W quartz-halogen light source was focused into samples of whole fruit and the transmitted radiation collected, spectrally dispersed, and focused onto a 2048-pixel linear charge-coupled device. The dual-prism configuration demonstrated a relatively uniform wavelength-independent optical transmission efficiency and dispersion. In comparison, the diffraction grating efficiency was a non-linear function of wavelength, blaze angle, incident angle, and coating material. Hence, although all designs performed adequately, the dual-prism instrument demonstrated a higher potential for more reliable, rapid sorting than those based on either the diffraction grating or the single prism.