Optimization of Purslane Plant Using Cooking and Pickling Processes for Reducing Oxalate Conten

Abstract

Purslane (Portulaca oleracea) is an edible plant rich in beneficial nutrients. Chemical composition, mineral composition, fatty acids, total phenolic compounds and radical scavenging activity of purslane were determined. In addition, oxalate content of purslane was analyzed after cooking at three temperatures (60, 80 and 100 °C) for different durations (5, 10, 15 and 20 minute), and pickling for various durations (3, 6 and 9 days). Fatty acid analysis, sensory evaluation and quality characteristics of biscuits fortified by purslane powder, after oxalate reduction treatment, were carried out. Ash, fiber, protein and fat contents of were 23.42, 16.03, 5.64 and 5.30 %, respectively on dry matter basis. Of the elements, potassium had the highest concentration (4694.0 mg K/100g), while zinc was found in the lowest concentration (0.93 mg Zn/100g). Total phenolics of purslane were 193.22 mg/100g gallic acid equivalent and radical scavenging activity was 87.29 %. The proportion of unsaturated fatty acids in purslane is high; linolenic acid represents 40.4 % of total fatty acids. The soluble fraction of total oxalate in purslane cooked for 20 minutes at 60, 80 and 100 °C were 34.65, 19.84 and 15.84 %, respectively. While after pickling for 0, 3, 6 and 9 days, the soluble fraction of total oxalate of purslane was 47.80, 36.23, 25.60 and 14.39 %, respectively. Addition of purslane powder after oxalate reducing treatments improved the quality characteristics of wheat flour biscuits. Portulaca oleracea is a good source of minerals, nutrients, antioxidants and omega-3 fatty acids, especially for functional food and nutraceutical applications.

Commercial Cultivation of Edible Halophytes: The Issue of Oxalates and Potential Mitigation Options

“…Blanching has been shown to be effective in removing oxalates from vegetables [49] In a study of the edible halophyte Portulaca oleracea, boiling the leaves, stems, or flowe buds for five minutes reduced the total oxalate in the tissues by, on average, 27% [50]. In a similar study on P. oleracea, Badawy et al [51] showed that as the heating time and tem perature were increased, soluble oxalate levels in the tissue decreased concomitantly Blanching the leaves of the halophyte Tetragonia expansia reduced the total oxalate by 25% when they were placed into boiling water for two minutes [52]. Pickling leaves in vinega has also been successfully used to reduce the oxalate content, although to a lesser exten than blanching [50,51].…”

“…Blanching the leaves of the halophyte Tetragonia expansia reduced the total oxalate by 25% when they were placed into boiling water for two minutes [52]. Pickling leaves in vinegar has also been successfully used to reduce the oxalate content, although to a lesser extent than blanching [50,51]. While blanching is an option for the removal of oxalates from leaves, it causes wilting due to breakdown of the tissue, and it is therefore not recommended when crisp salad leaves are the desired product.…”

مدى إمکانیة استخدام الرجلة الطازجة فی علاج فئران التجارب المصابة بالسمنة

“…Purslane is a common, herbaceous succulent annual plant. It is distributed extensively in temperate and tropical regions worldwide (Badawy et al, 2018 andPetroplous et al, 2019). In Egypt it's commonly known as "Rejlah" (El-Gindy, 2017).…”

“…In current years, it has been re-evaluated as a potential "New Crop" for its positive properties which distinguish as one of the best vegetable sources of omega-3 fatty acids (linolenic acid) and for its great crude protein and water-soluble polysaccharide contents. (Badawy et al, 2018 andPetroplous et al, 2019). It has been informed to possess various pharmacological activities; it has been used throughout history for several different medicinal purposes.…”

“…Moreover, it's a rich source of important nutrients such as fibers, ash, protein, carbohydrates, energy, minerals as calcium, copper, potassium, zinc, phosphorus, manganese, iron, and sodium, also it contains vitamins such as A, C, E and B complex. (Badawy et al, 2018). Purslane leaves contain high amounts of polyunsaturated fatty acids (omega-3 and omega-6).…”