Instrumental analysis and sensory evaluation are two fundamental approaches used to assess the quality of food products, encompassing attributes such as appearance, smell, flavor, and physical properties

Total phenolic content (TPC), total flavonoid content (TFC), ferric reducing antioxidant potential (FRAP), and diphenyl-1-picrylhydrazyl (DPPH) free radical scavenging activity of avocado peel, avocado seeds, kiwi fruit, orange peel, pineapple peel, and pomegranate skin by-products during processing (i.e., dried, blanched, freezed, and fresh) were determined. It was hypothesized that fruit by-products would add a significant value to the food products. Heat treatments resulted in increasing TPC and TFC and reducing power of fruit by-products with avocado peels TFC of 136.9 and 63.1mg/100g of dried and blanched treatments, respectively, compared to 14.4mg/100g of fresh and 20.6mg/100g of freezed treatments. Orange peels TFC increased from 54.4mg/100g of fresh to 194.4 and 380.0mg/100g for blanched and dried treatments, respectively. Fresh treatments had the lowest DPPH () (IC₅₀), indicating a significant effect of blanching and drying on fruit by-product antioxidant activity with some exceptions. IC₅₀ increased from 20.0 of fresh to 39.8 of dried pineapple peel and from 6.5 to 15.0 for pomegranate skin of fresh and dried treatments, respectively. The use of fruit by-products regardless to its processing as supplements to flours would significantly increase flours bioactive availability.

Simultaneous Determination of B₁, B₂, B₃, B₆, B_9, and B₁₂ Vitamins in Premix and Fortified Flour Using HPLC/DAD: Effect of Detection Wavelength: Simultaneous determination of water-soluble B vitamins is a troublesome analytical procedure since they have greatly variable structures and acid-base properties which imposed difficulties on eluting them in short time and selecting wavelength of detection. The aim of the present study was to develop a simple method that overcomes these difficulties. The method was successful in simultaneous determination of B₁, B₂, B₃, B₆, B₉, and B₁₂ in premix and fortified flour by extracting vitamins with 0.1 (w/v) of ascorbate and ethylene diamine tetra-acetic acid (EDTA) solution followed by eluting using gradient mobile phase consisting of 0.03 trifluoroacetic acid aqueous solution (pH 2.6) and acetonitrile on high performance liquid chromatography (HPLC) instrument coupled with diode array detector (DAD). Elution of vitamins was completed within 9.3min, and the lowest values obtained for limit of quantification (LOQ) for B₁, B₂, B₃, B₆, B₉, and B₁₂ were 0.6, 0.2, 0.8, 0.3, 0.5, and 0.7μg/mL, respectively, at four wavelengths of 361, 280, 265, and 210nm. In general, variation of wavelength of detection in the range from 210 to 361nm affects sensitivity but had a marginal effect on the linearity and LOQ of the developed method and its application for determining B vitamins in premix and fortified flour. The 210nm wavelength exhibited the highest sensitivity though resulted in higher values of B vitamins in fortified flour with respect to 265, 280, and 361nm. Noteworthy, determination of B₂ and B₁₂ in the premix at 361nm had relatively high RSD values compared to the lower wavelengths. Thus, wavelengths in the range from 265 to 280 may be more favorable over 210 and 361nm. The method reported in the present work does not require any sample cleanup/preconcentration steps, and chromatographic elution was achieved in 9.3min without the need for ion-pairing reagents.