Food Storage Metabolomics

Understanding the Challenge of Food Spoilage

Throughout the storage and retail phases of food products, the interplay of factors such as oxygen, microorganisms, temperature, humidity, and light often instigates changes in color, aroma, flavor, and nutritional composition. These alterations can, in certain instances, result in food spoilage, diminishing both the nutritional value and sensory qualities of the product. The fundamental cause of these variations lies in the transformation of constituents within the food matrix. Extended storage periods, for example, may lead to flavor modifications primarily attributed to the reduction of aromatic compounds and the amplification of undesirable off-flavors. Consequently, the focal point in food research consistently revolves around the crucial task of extending the shelf life of food products.

Approaches to Food Preservation

In the realm of food preservation research, two prevailing approaches take center stage. One avenue involves the exploration of external preservation methodologies, such as the application of fucoidan ^[1]. The alternative pathway addresses the issue at its source by directly manipulating the intrinsic characteristics of the food through genetic modifications. Illustrating this approach, Professor Cathie Martin's laboratory has conducted multifaceted studies in the realm of genetic enhancement, particularly focusing on tomatoes. The incorporation of genetic elements from snapdragon and transcription factors from Arabidopsis thaliana notably increased the accumulation of anthocyanins in tomatoes. This transformative outcome concurrently extended the shelf life of tomatoes ^[2,3]. This genetic intervention strategy offers an environmentally conscious means of optimizing preservation efficacy.

Metabolomic Insights into Kiwifruit Preservation

Here, we take pleasure in highlighting the article 'Widely targeted metabolomics analysis reveals the effect of exogenous auxin on postharvest resistance to Botrytis cinerea in kiwifruit (Actinidia chinensis L.)' that intricately employs metabolomic profiling to explore methodologies combating spoilage. This research significantly contributes to ongoing endeavors aimed at preserving the qualitative attributes and integrity of food products.

Kiwifruit, hailed as the "king of fruits," is rich in vitamin C, fiber, serotonin, carotenoids, and boasts significant antioxidant properties. One medium-sized kiwi (75g) provides 42 calories, 0.1g of protein, 10.1g of carbohydrates, and 0.4g of fat.. The nutrition information is provided by the USDA^[4]. Despite its nutritional benefits, kiwifruit is susceptible to fungal infections postharvest, leading to softening and deterioration. In this study, to decipher whether postharvest treatment with Indole-3-acetic acid (IAA) effectively delays fungal infection by Botrytis cinerea and elucidate the associated mechanisms, IAA treatment was chosen for postharvest kiwifruit, with two treatments (IAA and IAA+B. cinerea infection) at three different time points, resulting in a total of five sample groups for metabolomic analysis.

Using MetwareBio's proprietary Widely-Targeted Metabolomics for Plants, a total of 776 compounds were identified, with alkaloids, flavonoids, and phenols ranking as the top three, collectively constituting 30.93% of all compounds. Besides, IAA treatment induced the accumulation of different types of compounds at various time points. Notably, flavonoids such as rhoifolin and trimethylapigenin exhibited sustained accumulation during IAA treatment. Rhoifolin demonstrated excellent antioxidant activity^[5], while trimethylapigenin exhibited antibacterial properties^[6], suggesting that IAA treatment activates immune-related pathways in kiwifruit. B. cinerea infection can induce flavonoids and alkaloids accumulated. Following IAA treatment and subsequent B. cinerea infection for 72 hours, (-)-epigallocatechin continued to accumulate.

In summary, when faced with fungal infection, kiwifruit not only activates antioxidant enzymes but also synthesizes various antioxidant compounds to slow down the progression of fungal infection. Exogenous application of IAA proves beneficial in rapidly triggering the plant's immune response. The studies above underscore the utility of metabolomics in researching the quality, nutrition, and stress response of foods.

References:

1. Zhang Y, Lin D, Yan R, Xu Y, Xing M, Liao S, Wan C, Chen C, Zhu L, Kai W, Chen J, Gan Z. Amelioration of Chilling Injury by Fucoidan in Cold-Stored Cucumber via Membrane Lipid Metabolism Regulation. Foods. 2023 Jan 8;12(2):301.

2. Zhang Y , Butelli E , Alseekh S , et al. Multi-level engineering facilitates the production of phenylpropanoid compounds in tomato[J]. Nature Communications, 2015. Oct 26;6:8635.

3. Zhang Y, De Stefano R, Robine M, Butelli E, Bulling K, Hill L, Rejzek M, Martin C, Schoonbeek HJ. Different Reactive Oxygen Species Scavenging Properties of Flavonoids Determine Their Abilities to Extend the Shelf Life of Tomato. Plant Physiol. 2015 Nov;169(3):1568-83.

4. Drummond L. The composition and nutritional value of kiwifruit. Adv Food Nutr Res. 2013;68:33-57. 

5. Zengin G, Mostafa NM, Abdelkhalek YM, Eldahshan OA. Antioxidant and Enzyme Inhibitory Activities of Rhoifolin Flavonoid: In Vitro and in Silico Studies. Chem Biodivers. 2023 Sep;20(9):e202300117.

6. Maia GL, Falcão-Silva Vdos S, Aquino PG, de Araújo-Júnior JX, Tavares JF, da Silva MS, Rodrigues LC, de Siqueira-Júnior JP, Barbosa-Filho JM. Flavonoids from Praxelis clematidea R.M. King and Robinson modulate bacterial drug resistance. Molecules. 2011 Jun 10;16(6):4828-35.