تاثیر واریته و روش تهیه بر خصوصیات فیزیکی و شیمیایی نوشیدنی هسته خرما

زمینه مطالعاتی: برشته کردن هسته خرما، روشی ساده و ارزان جهت ایجاد ارزش افزوده بر هسته خرما است که با وجود ارزش غذایی بالا معمولا دور ریخته می‌شود. هدف: در این پژوهش تاثیر واریته و روش تهیه بر خصوصیات فیزیکی و شیمیایی نوشیدنی هسته خرمای برشته مورد مطالعه قرار گرفت. روش کار: خواص آنتی‌اکسیدانی، محتوای فنول، فلاونوئید، کافئین، ملانوئیدین، و پارامترهای رنگی و ph سه نوع نوشیدنی (اسپرسو، جوشیده و فیلتر) حاصل از هسته خرمای برشته (شاهانی و مضافتی) مورد بررسی قرار گرفته و با قهوه عربیکا مقایسه شدند. نتایج: تفاوت قابل توجه میان واریته‌های شاهانی و مضافتی به لحاظ فلاونوئید (ml100/mg 68 11)، فنول (ml100/mg 194 37)، و ملانوئیدین (ml100/mg 62 26) مشاهده شد. در روش تهیه یکسان، تفاوتی بین محتوای کافئین این دو واریته (ml100/mg 1.0 0.2) مشاهده نگردید. بیشترین قدرت مهار رادیکال آزاد dpph (l/mmol trolox 14) و بالاترین قدرت احیاکنندگی آهنiii (l/mmol fe+2 32) در نوشیدنی اسپرسوی هسته خرما شاهانی بدست آمد. انواع قهوه دارای محتوای فلاونوئید (ml100/mg 200 32)، فنول (ml100/mg 328 52)، ملانوئیدین (ml100/mg 262 115)، کافئین (ml100/mg 75 36)، قدرت مهار رادیکال آزاد (l/mmol trolox 13 2) و قدرت احیاکنندگی آهنiii (l/mmol fe+2 32 16) بالایی بودند. ph انواع قهوه (5.5 5.3) بیشتر از انواع نوشیدنی هسته خرما (5.02 4.64) و رنگ آن‌ها نیز تیره‌تر (l* ، 33 20) از انواع نوشیدنی هسته خرما (l* ، 82 45) گزارش شد. در خصوص تاثیر روش تهیه نیز، بیشترین مقادیر پارامترهای اندازه‌گیری شده به ترتیب مربوط به نوشیدنی اسپرسو، جوشیده و سپس فیلتر بود. نتیجه‌گیری نهایی: نتایج نشان دادند که روش تهیه و نوع واریته جهت تهیه نوشیدنی هسته خرما تاثیر معناداری بر خواص شیمیایی و فیزیکی آن و احتمالا پذیرش نوشیدنی از سمت مصرف‌کنندکان دارد. همچنین اگرچه هسته خرما در مقایسه با قهوه عربیکا خواص آنتی‌اکسیدانی، ملانوئیدن، ph کمتر و رنگ روشن‌تری داشت، ولی به دلیل حضور مقادیر ناچیز کافئین، می‌تواند جامعه هدف خاص خود را داشته باشد.

impact of variety and brewing method on physical and chemical properties of date seed brew

introduction: date seed is considered as one of the most important wastes in the date processing industry which despite its high nutritional value, it is usually disposed of. this results in environmental contamination that require high cost to resolve. on the other hand, waste valorization in the food industry is important both in terms of environmental and economic benefits. studies indicated that date seeds have a high nutritional value and could be considered as a good source of bioactive compounds (platat, habib, al maqbali, jaber, & ibrahim, 2014). the amount of dietary fiber in different types of date seeds varies between 20 to 80% w/w (al juhaimi et al., 2018). date seeds also contain 5.9 9.9% w/w protein (bouaziz et al., 2008) and 5 13 w/w oil (nehdi et al., 2010). the antioxidant properties of date seeds are also derived from its components such as vitamin e, beta carotene and phenolic compounds. thus, date seeds have the potential to be used as an ingredient in other foods, directly or indirectly (al farsi et al., 2007). one of the relatively inexpensive ways to added value on date seed is to prepare a beverage from roasted date seed powder. the roasting process enhances the flavor of the brew, increases the shelf life of the product. it is hypothesized that roasting can lead to an alternative product for those who want to enjoy a somewhat coffee like brew without caffeine (fikry et al., 2019; ghnimi, almansoori, jobe, hassan, & kamal, 2015). however, as it has been reported in terms of coffee, method of brewing and bean varieties can make a difference in the antioxidant properties of the final product (vignoli, bassoli, & benassi, 2011). as a result, in this study, the effect of variety and method of preparation on the antioxidant properties of beverage obtained from roasted date seeds was investigated, which has not been mentioned so far. for this purpose, two types of date seed (shahani and mazafati) were used to prepare espresso, boiled and filtered brews and the results were compared with respective arabica coffee brewsmaterials and methods: arabica coffee (coffea arabica) and two types of shahani and mazafati dates were purchased from local stores in mashhad, iran. three types of coffee brews including espresso, boiled and filtered brew were prepared. in this study, the antioxidant properties, phenolic and flavonoid content, caffeine, melanoidin, color parameters and ph of brews (espresso, boiled and filtered) were studied.results and discussion: the phenolic content in mazafati and shahani and arabica coffee brews were in the range of 37 102, 41 194 and 52 328 mg/100 ml, respectively. the method of preparation also has a significant effect on the extraction of phenolic compounds, as the content of phenolic compounds in coffee increased from 52.94 prepared via the filter method to 328.33 mg in 100 ml of espresso coffee. in the present study, the total flavonoid content in mazafati, shahani and arabica coffee brews were 11 30, 14 68 and 32 200 mg/100 ml of beverage, respectively. the decrease in the content of phenolic as well as flavonoid content in date seed beverages can be attributed to both the lower amount of these compounds in the powders and the lower rate of their extraction. the results of olechno et al. (2020) indicate a significant effect of the preparation method on various phenolic compounds content in coffee. the reducing power of fe+3 in beverages obtained from shahani date seed was almost twice that of found in mazafati date seed.