Vitamins and minerals are essential micronutrients required in small quantities for normal physiological function. Unlike macronutrients, they do not provide energy but serve as cofactors, antioxidants, and structural components. Their retention during food processing and accurate quantification are major concerns in food science.
Fat-Soluble Vitamins
Vitamin A (retinol, beta-carotene) is essential for vision and immune function. It is sensitive to oxidation and light, particularly in the presence of unsaturated lipids. Vitamin D (calciferol) is synthesized in the skin upon UV exposure and is crucial for calcium metabolism. Vitamin E (tocopherols and tocotrienols) functions as a chain-breaking antioxidant, protecting polyunsaturated fatty acids from lipid peroxidation. Alpha-tocopherol is the most biologically active form. Vitamin K (phylloquinone, menaquinone) is necessary for blood coagulation and bone metabolism.
Water-Soluble Vitamins
The B-complex vitamins include thiamine (B1), riboflavin (B2), niacin (B3), pantothenic acid (B5), pyridoxine (B6), biotin (B7), folate (B9), and cobalamin (B12). They function primarily as coenzymes in metabolic pathways. Thiamine is heat-labile and losses during cooking can be substantial. Folate is highly sensitive to oxidation, UV light, and leaching into cooking water. Vitamin C (ascorbic acid) is a potent antioxidant and is readily degraded by heat, oxygen, light, and metal ions.
Bioavailability and Processing
Bioavailability refers to the fraction of an ingested nutrient that is absorbed and utilized. Fat-soluble vitamins require dietary fat for optimal absorption. Processing conditions such as heating, exposure to light, pH extremes, and oxidation can significantly reduce vitamin content. For example, pasteurization causes approximately 10–20% loss of vitamin C, while canning can result in 50–90% loss.
Macro and Trace Minerals
Major minerals (calcium, phosphorus, magnesium, sodium, potassium, chloride) are required at levels exceeding 100 mg per day. Calcium is essential for bone health and is particularly abundant in dairy products. Trace minerals (iron, zinc, selenium, iodine, copper, manganese, fluoride, chromium, molybdenum) are required in smaller amounts. Iron deficiency is the most widespread nutritional disorder worldwide. Zinc is important for immune function and wound healing, while selenium is an essential component of antioxidant enzymes.
Analytical Methods
Inductively coupled plasma mass spectrometry (ICP-MS) and inductively coupled plasma optical emission spectroscopy (ICP-OES) are the gold standards for multi-element mineral analysis, offering high sensitivity and wide dynamic range. Atomic absorption spectroscopy (AAS) is a traditional technique still used for single-element analysis of metals such as calcium, iron, and zinc. HPLC coupled with UV, fluorescence, or mass spectrometric detection is employed for vitamin analysis, with specific methods tailored to each vitamin’s chemical properties. Microbiological assays are historically used for certain B vitamins but are increasingly replaced by instrumental methods. Vitamin analysis typically employs HPLC with UV or fluorescence detection, while mineral analysis uses atomic spectroscopy techniques such as AAS and ICP-MS. Total mineral content is estimated through ash content determination.
