Maltose

Maltose is a disaccharide composed of two glucose units linked by an α-1,4 glycosidic bond^[1]. Maltose can be produced by the breakdown of starch, is slightly sweet (less sweet than sucrose), soluble in water, and exists in α and β isomers^[2]. The applications of Maltose span various fields such as food, biology, and daily chemicals, primarily as a sweetener, fermentation sugar in beer brewing, a carbon source for cell culture, and a humectant in skincare products^[3].

In vitro, when barley microspore were cultured with Maltose (40mM) for 6-24h, compared to sucrose, Maltose exhibited slower metabolic rates, lower ethanol accumulation, higher energy status, supported cell survival, and promoted embryogenesis^[4]. Maltose (2.5-112mM) incubated with isolated pea thylakoids at -15℃ for 20h protected the activity of the electron transport chain, with a protection rate of 93% at 112mM, significantly outperforming glucose^[5]. Treatment of human intestinal epithelial Caco-2/TC7 cells with Maltose (12.5mM) for 24h upregulated the expression of the sucrase-isomaltase (SI) gene in a time-dependent manner^[6].

In vivo, male C57BL/6J mice continuously fed a high-fat diet containing 7% Maltose (by weight) for 13 weeks showed more pronounced increases in fasting blood glucose, plasma total cholesterol, high-density lipoprotein (HDL) cholesterol, and non-HDL cholesterol levels compared to mice fed only a high-fat diet^[7]. Normal C57BL/6J mice orally administered Maltose (2g/kg) after overnight fasting exhibited a significant postprandial blood glucose elevation, peaking at 30min, and produced a high area under the curve (AUC) for blood glucose^[8].

References:
[1] QUIGLEY G J, SARKO A, MARCHESSAULT R H. Crystal and molecular structure of maltose monohydrate[J]. Journal of the American Chemical Society, 1970, 92(20): 5834-5839.
[2] KHAN R. The chemistry of maltose[M]//Advances in Carbohydrate Chemistry and Biochemistry. Academic Press, 1981, 39: 213-278.
[3] CARLSEN M, NIELSEN J. Influence of carbon source on α-amylase production by Aspergillus oryzae[J]. Applied Microbiology and Biotechnology, 2001, 57(3): 346-349.
[4] SCOTT P, LYNE R L, AP REES T. Metabolism of maltose and sucrose by microspores isolated from barley (Hordeum vulgare L.)[J]. Planta, 1995, 197(3): 435-441.
[5] KAPLAN F, GUY C L. β-Amylase induction and the protective role of maltose during temperature shock[J]. Plant Physiology, 2004, 135(3): 1674-1684.
[6] CHENG M W, CHEGENI M, KIM K H, et al. Different sucrose-isomaltase response of Caco-2 cells to glucose and maltose suggests dietary maltose sensing[J]. Journal of Clinical Biochemistry and Nutrition, 2014, 54(1): 55-60.
[7] SHIBAZAKI N, TANAKA W, SUZUKI Y, et al. Maltose consumption exacerbates high-fat diet-induced overweight and related parameters in mice[J]. Functional Foods in Health and Disease, 2022, 12(11): 680-692.
[8] KIM J I, BAEK H J, HAN D W, et al. Autumn olive (Elaeagnus umbellata Thunb.) berry reduces fasting and postprandial glucose levels in mice[J]. Nutrition Research and Practice, 2019, 13(1): 11-16.

Maltose是由两个单位葡萄糖通过α-1,4糖苷键连接而成的二糖^[1]。Maltose可由淀粉分解形成，带有微甜（比蔗糖甜度低）且可溶于水，可形成α和β异构体^[2]。Maltose的应用涵盖食品、生物和日化等各个领域，主要用作甜味剂、啤酒发酵糖、细胞培养的碳源和护肤品保湿剂等^[3]。

在体外，Maltose（40mM）培养大麦花粉粒6-24h，与蔗糖相比，代谢速率较慢，乙醇积累少，能量状态较高，支持细胞存活并促进胚胎发生^[4]。Maltose（2.5-112mM）与分离的豌豆类囊体在-15℃冷冻20h，能保护电子传递链活性，在112mM时保护率达93%，显著优于葡萄糖^[5]。Maltose（12.5mM）处理人肠道上皮Caco-2/TC7细胞24h，可时间依赖性地上调蔗糖酶-异麦芽糖酶（SI）基因的表达^[6]。

在体内，雄性C57BL/6J小鼠持续摄入含质量百分比为7%Maltose的高脂饲料13周，较仅摄入高脂饲料的小鼠相比，其空腹血糖、血浆总胆固醇、高密度脂蛋白（HDL）胆固醇及非HDL胆固醇水平均出现更明显的升高^[7]。正常C57BL/6J小鼠过夜禁食后口服Maltose（2g/kg），诱导餐后血糖显著升高，在30min时达到峰值，并产生较高的血糖曲线下面积（AUC）^[8]。