You will be shown an abstract from a biomedical research paper. Given this abstract, your task is to extract all unique entities of the following types: ["Chemical"].

Please return the output as a JSON object of the format: {"Chemical": ["Arsenic", ...]}. The keys should be entity types and values should be lists of extracted entities belonging to the corresponding type. If you cannot find entities belonging to a specific type, the value should be [].

Only output the JSON object and do not include any additional text.

Abstract:

Nutritive value of masau (Ziziphus mauritiana) fruits from Zambezi Valley in Zimbabwe. Ziziphus mauritiana (masau) fruits are consumed by many people in Zimbabwe. The fruits contribute significantly to people's diet when they are in season. The objective of this study was to determine the nutritional content of the fruits and, hence, quantify their contribution to the diet. Samples of masau were collected in two seasons (August 2006 and August 2007). Both macronutrients and micronutrients were determined using standard AOAC methods of analysis. Dry matter content ranged from 21.1±0.2 to 24.1±0.3 g 100 g(-1) of edible portion of the sweet and sour fruits, and 84.8±0.2 to 87.2±0.2 g 100 g(-1) for the dried fruit. Crude protein per 100g edible portion of dry weight ranged between 7.9±0.0 and 8.7±0.0 g, crude fat from 0.8±0.0 to 1.5±0.0 g, crude fibre from 4.9±0.0 to 7.3±0.0 g, ash between 3.0±0.0 and 4.3±0.0 g and carbohydrate between 79.5±0.0 and 83.2±0.0 g. The fruits were rich in vitamin C (15.0±0.0-43.8±0.02 mg 100 g(-1)) and the energy values ranged between 1516.0±1.73 and 1575.0±2.3 kJ 100 g(-1). Furthermore, the fruits contained (mg 100 g(-1) of dry weight) potassium from 1865.0±1.3 to 2441.0±1.1, calcium from 160.0±0.3 to 254.0±0.1, sodium between 185.0±0.1 and 223.0±0.2, magnesium between 83.0±0.0 and 150.0±0.13 and phosphorous from 87.0±0.1 to 148.0±0.5. Manganese and copper contents ranged between 0.7±0.03 and 1.6±0.03, while iron and zinc ranged between 2.1±0.43 and 4.3±0.1, and 0.6±0.0-0.9±0.0 mg 100 g(-1) of dry weight, respectively. The masau fruit is therefore a good potential source of carbohydrates, proteins and micronutrients, such as calcium, potassium, sodium, phosphorous, copper, iron, Vitamin C and zinc.
{"Chemical": ["zinc", "carbohydrates", "Vitamin C", "sodium", "carbohydrate", "calcium", "iron", "potassium", "copper", "vitamin C", "Manganese", "magnesium", "phosphorous"]}