Objective With the rise of industrialized dishes, the quality differences between industrial and traditional hand-cooked modes are a major concern for the food industry and consumers. This study examined the nutrient content variations in Chinese cuisines between these two cooking modes, addressing a crucial research gap. Methods To account for moisture changes during cooking, water content in both raw ingredients and cooked dishes was adjusted, and nutrients were reported on a dry matter basis. The changes in nutrient content pre- and post-cooking were assessed by calculating the relative percentage of nutrient content in the cooked dishes in comparison to their levels in the raw ingredients. An independent t-test was employed to assess the significance of differences in the changes in nutrient content between industrial and traditional hand-cooked modes. Results Macronutrient levels remained relatively stable, with changes of less than 20% across most dishes for both cooking methods, with some exceptions noted. Fat-soluble vitamins A and D exhibited minor fluctuations, ranging from 2.6 to 39.4%, while vitamin E levels consistently increased. In contrast, water-soluble vitamins, specifically B1, B2, B3, and B6, experienced substantial decreases across all examined dishes. The fatty acid profiles were consistent with the fat content, and mineral content demonstrated a moderate increase under both cooking conditions. An inter-group t-test indicated no significant differences in nutrient content changes between the two cooking modes (p > 0.05), except for vitamin B6 retention, which was significantly lower in traditional hand-cooked modes compared to industrial modes (p < 0.05). Conclusion Among the six Chinese cuisines analyzed, the changes in nutrient content did not significantly differ between industrial and traditional cooking methods, with the notable exception of vitamin B6 retention. These findings contribute to a deeper understanding of how different cooking techniques impact the nutritional value of food, providing valuable insights for dietary decision-making and food processing technologies.

Purpose: The objective of this study was to subject African nightshade and vegetable Amaranth to different household cooking methods (boiling, steaming, microwave and stir frying) and  test them on the changes of total phenolic content (TPC), antioxidant property (ferric reducing-antioxidant power (FRAP) activity and DPPH radical scavenging activity), macronutrients and micronutrients. Methodology: The African nightshade, (HB) and the Amaranthus leaves, (AL) used in the preparation of all the dishes were purchased from the same farmer at Nkwen in Mezam division of the North West Region of Cameroon. Standard methods were used to determine each analyte at the Laboratory of Food Science and Metabolism (LabSAM) of the University of Yaounde 1 and Nkolbisson Food Technology Laboratory, Yaounde, Cameroon. Findings: The TPC of leafy vegetables ranged from 256.64 to 1184.08 mg GAE/100g, with higher levels observed in cooked forms compared to raw ones. Steaming significantly increased FRAP in both African nightshade and amaranth, followed by microwaving and boiling, with steamed samples showing the highest antioxidant activity. Cooking methods also enhanced DPPH free radical scavenging activity, with microwaved African nightshade (HBM) and steamed amaranth (ALS) exhibiting the highest activity. Nutritional analysis revealed variations in dry matter, ash, protein, crude fiber, and total sugars, with steamed vegetables (ALS, HBM, HBS) generally having higher nutrient levels. Mineral and vitamin analyses showed iron (19.08–34.87 mg/100g DW), zinc (1.06–3.92 mg/100g DW), vitamin C (93.85–231.42 mg/100g DW), and provitamin A (16.5–62.85 mg/100g DW) levels were higher in cooked vegetables compared to their raw counterparts. Unique contribution to theory, practice and policy: This study demonstrates that different cooking techniques impact the nutritional composition and antioxidant activities of the indigenous vegetables; African nightshade and vegetable amaranth. The findings provide valuable insights for optimizing the cooking methods of these vegetables to enhance their health benefits. Thus this study greatly contributes to providing healthy choices on the different ways in which these vegetables can be cooked.

Mineral contents of the autoclaved bean samples were generally similar to those of the raw (unprocessed) samples. Under the processing conditions, roasting caused the highest reduction in thioglucoside content (59%) in soya bean while cooking caused the highest reduction in lima bean (78%). Trypsin inhibitor activity (TIA) ranged between 0.59 mg/g sample in the cooked soya bean and 11.6 mg/g sample in the raw bean while the corresponding values for lima bean ranged between 0.59 and 6.3 mg/g sample. Cooking and roasting caused over 90% reduction of TIA, while autoclaving caused 64-69% reduction in both bean samples. Under the assay conditions, haemagglutinating activity was not detected in the cooked and autoclaved soya and lima beans. The need to prevent both functional and nutritional damage to food proteins and other nutrients, resulting from excessive heating, was discussed. Published in Die Nahrung (1989)

Effect of different cooking methods on the content of vitamins and true retention in selected vegetables - PMC Food Sci Biotechnol . 2017 Dec 12;27(2):333–342. doi: 10.1007/s10068-017-0281-1 # Effect of different cooking methods on the content of vitamins and true retention in selected vegetables 2, Heon Sang Jeong 1,✉ - Author information - Article notes - Copyright and License information 1Division of Food and Animal Sciences, College of Agriculture, Life, and Environmental Sciences, Chungbuk National University, 1 Chungdae-ro, Seowon-gu, Cheongju, Chungbuk 28644 Korea 2National Academy of Agricultural Science, Rural Development Administration, Jeonju, Jeonbuk 55365 Korea ✉ Corresponding author. Received 2017 May 25; Revised 2017 Nov 17; Accepted 2017 Dec 2; Collection date 2018 Apr. © The Korean Society of Food Science and Technology and Springer Science+Business Media B.V., part of Springer Nature 2017 PMCID: PMC6049644 PMID: 30263756 ## Abstract This study evaluated the effect of different cooking methods including blanching, boiling, microwaving and steaming on the content of vitamins in vegetables. True retention was estimated using the yield expressed as a ra