Nutritional Analysis and Determination of Heavy Metal Content of Some Spices from the Northern Region, Bangladesh

Abstract

Spices are generally consumed because of their medicinal properties, taste, and add flavor to food. Objectives: To determine the nutrient contents and heavy metals of five commonly consumed spices, namely turmeric ( Curcuma longa ), bay leaf ( Laurus nobilis ), red chili ( Capsicum annuum ), coriander ( Coriander sativum ), and black cumin ( Nigella sativa ) were collected from the local market of Northern zone, Bangladesh and were analyzed. Methods: Nutrient composition was assessed by proximate analysis, trace and heavy metals by atomic absorption spectrophotometry while the indophenol method was used to determine vitamin C. Result: The results revealed that spices are good sources of carbohydrate, fiber, and fat. The highest levels of carbohydrates, dietary fiber, protein, and fat were observed in turmeric (71.1%), black cumin (40.0%), red chili (16.77%), and coriander (17.8%) respectively. Vitamin C was present in trace amounts ranging from 0 .04 to 0.1 mg/100g, except black cumin (35.0 mg/100g). Essential trac e minerals like sodium, potassium, calcium, magnesium, and iron were significantly present in black cumin and bay leaf. Most of the heavy metal levels in the spices were appreciable amounts i.e. much lesser than the statutory safe limit approved by WHO and FAO for some of the samples. Conclusion: The current study concluded that the investigated spices are nutritionally rich, and heavy metal levels in the examined samples are safe for human consumption.