Prochaska L J, Nguyen X T, Donat N, Piekutowski W V
Department of Biochemistry & Molecular Biology, School of Medicine, Wright State University, Dayton, OH, USA.
Med Hypotheses. 2000 Feb;54(2):254-62. doi: 10.1054/mehy.1999.0030.
One of the goals of our society is to provide adequate nourishment for the general population of humans. In the strictness sense, the foodstuffs which we ingest are bundles of thermodynamic energy. In our post-industrial society, food producers provide society with the bioenergetic content of foods, while stabilizing the food in a non-perishable form that enables the consumer to access foods that are convenient and nutritious. As our modern society developed, the processing of foodstuffs increased to allow consumers flexibility in their choice in which foods to eat (based on nutritional content and amount of post-harvest processing). The thermodynamic energy content of foodstuffs is well documented in the literature by the use of bomb calorimetry measurements. Here, we determine the effects of processing (in most cases by the application of heat) on the thermodynamic energy content of foods in order to investigate the role of processing in daily nutritional needs. We also examine which processing procedures affect the nutritive quality (vitamin and mineral content) and critically assess the rational, advantages and disadvantages of additives to food. Finally, we discuss the role of endogenous enzymes in foods not only on the nutritive quality of the food but also on the freshness and flavor of the food. Our results show that a significant decrease in thermodynamic energy content occurs in fruits, vegetables, and meat products upon processing that is independent of water content. No significant change in energy content was observed in cereals, sugars, grains, fats and oils, and nuts. The vitamin content of most foods was most dramatically decreased by canning while smaller effects were observed upon blanching and freezing. We found that most food additives had very little effect on thermodynamic energy content due to their presence in minute quantities and that most were added to preserve the foodstuff or supplement its vitamin content. The endogenous food enzymes while aiding in digestibility of some foods (yogurt or grains) also helped some foods have a more palatable taste. Our conclusions are there is some scientific merit to the idea that enzymes in food can act synergistically with those in the human body to facilitate maximum nutritive value of foods.
我们社会的目标之一是为广大人类群体提供充足的营养。从严格意义上讲，我们摄入的食物是热力学能量的集合。在我们的后工业社会，食品生产者为社会提供食物的生物能量成分，同时将食物稳定在不易腐烂的形式，使消费者能够获取方便且营养丰富的食物。随着现代社会的发展，食品加工不断增加，以便消费者能够根据营养成分和收获后加工量灵活选择食用的食物。通过使用弹式量热法测量，食品的热力学能量含量在文献中有充分记录。在此，我们确定加工（在大多数情况下通过加热）对食物热力学能量含量的影响，以研究加工在日常营养需求中的作用。我们还研究哪些加工程序会影响营养质量（维生素和矿物质含量），并严格评估食品添加剂的合理性、优点和缺点。最后，我们讨论食物中内源性酶不仅对食物营养质量，而且对食物的新鲜度和风味所起的作用。我们的结果表明，水果、蔬菜和肉类产品在加工后热力学能量含量显著下降，且与水分含量无关。谷物、糖类、谷物、油脂和坚果的能量含量未观察到显著变化。大多数食物的维生素含量在罐装时下降最为显著，而在热烫和冷冻时影响较小。我们发现大多数食品添加剂由于用量极少，对热力学能量含量影响很小，且大多数添加剂是为了保存食物或补充其维生素含量而添加的。食物中的内源性酶在帮助某些食物（酸奶或谷物）消化的同时，也使一些食物口感更佳。我们的结论是，食物中的酶可以与人体中的酶协同作用以促进食物最大营养价值的观点具有一定的科学价值。
