Kosheleva O V, Kodentsova V M
Vopr Pitan. 2013;82(3):45-52.
Strong opinion about reducing vitamin C content in traditional cultivars of fruits and vegetables as a result of intensive farming practices, on the one hand, and depletion of soil, waste of fertilizers, on the other hand, takes place. The aim of the study was to assess changes in vitamin C content in fresh vegetables, fruits and berries from the 40s of last century to the present. Available national and foreign data from official tables of the chemical composition tables published in different years, including the most typical values, based on the results conducted in a number of research institutes, laboratories and university departments, as well as some original investigations and unpublished own results were used to analyze possible changes of vitamin C content in fruits and vegetables. For comparison we take into consideration only results from the most common and affordable since the last century method of visual titration, which has a relative error of 20%. Analysis of vitamin C content conducted according 5-58 studies from the 40s of the last century to the present, for 32 types of greens and vegetables (potatoes, various types of cabbage and onion, garlic, carrot, turnip, tomato, pepper, eggplant, cucumber, squash, peas, turnip, garden radish, parsnip, rhubarb, parsley, dill, lettuce, onion, spinach, sorrel), and according to 6-50 studies of 24 sorts of fruits (apple, pear, mandarin, orange, lemon, grapefruit, pineapple, banana, watermelon, cantaloupe, grapes, peach, apricot, plum, cherry, blackberry, blueberry, strawberry, raspberry, blackberry, gooseberry, black currant, red and white) has been done. It was found that the average content of vitamin varies slightly. Deviations from the average for all the years of research do not exceed the standard deviation. Analysis of longitudinal data did not confirm a vitamin C decrease. This means that vitamin value C of fruits and vegetables remains approximately constant, due to the successful selection of new varieties with increased vitamin value. Thus, the view of reducing the C-vitamin value in cultivars produce proved unfounded.
一方面,由于集约化种植方式,人们对降低传统果蔬品种中维生素C含量有强烈看法,另一方面,土壤养分流失、肥料浪费现象也存在。本研究的目的是评估从上世纪40年代到现在新鲜蔬菜、水果和浆果中维生素C含量的变化。利用不同年份出版的化学成分官方表格中的国内外现有数据,包括基于多个研究机构、实验室和大学部门的研究结果得出的最典型值,以及一些原始调查和未发表的自身研究结果,来分析水果和蔬菜中维生素C含量可能的变化。为作比较,我们仅考虑自上世纪以来最常用且经济实惠的目视滴定法的结果,其相对误差为20%。对上世纪40年代到现在的5 - 58项研究进行了维生素C含量分析,涉及32种绿叶蔬菜和蔬菜(土豆、各类卷心菜、洋葱、大蒜、胡萝卜、芜菁、番茄、辣椒、茄子、黄瓜、南瓜、豌豆、芜菁、水萝卜、防风草、大黄、欧芹、莳萝、生菜、洋葱、菠菜、酢浆草),并对24种水果(苹果、梨、柑橘、橙子、柠檬、葡萄柚、菠萝、香蕉、西瓜、哈密瓜、葡萄、桃子、杏子、李子、樱桃、黑莓、蓝莓、草莓、树莓、黑莓、醋栗、黑加仑、红醋栗和白醋栗)进行了6 - 50项研究。结果发现维生素的平均含量变化不大。所有研究年份与平均值的偏差均未超过标准差。纵向数据分析未证实维生素C含量下降。这意味着由于成功选育出维生素含量增加的新品种,水果和蔬菜中维生素C的含量大致保持恒定。因此,认为栽培品种中维生素C含量降低的观点被证明是没有根据的。