Abstract

Beet and cane molasses mainly contain mono- di-, and tri-saccharides, composed by hexoses, as well as pentoses in traces. However, rationing software consider sugars as only one entity, with a rate of digestion ∼20% h⁻¹. The aim of this initial study was to investigate and evaluate the in vitro digestion dynamics and rates of the sugar fraction in molasses. Three beet and three cane molasses were randomly selected from a variety of samples collected world-wide and digested via in vitro rumen fermentation, at 1, 2, 3, 4, 6, 8, and 24 h. Samples were then analysed with a specific enzymatic kit to quantify residual sucrose, glucose, fructose, raffinose, galactose, and arabinose. Complete disappearance of sucrose happened within 3 hours of incubation. Glucose and fructose were completely digested within 4-6 h, showing variability among samples. Even if not so representative, galactose showed a similar trend of digestion (97% digestion within 3-4 h). Raffinose was quite slower in cane molasses, while it was completely digested within 1 h in beet molasses. Arabinose, a pentose, never reached a complete digestion, and its fermentation dynamic was different compared to other sugars. Calculated rates of digestion for sucrose, glucose and fructose, most representative sugars in molasses, were higher than 50% h⁻¹ in both cane and beet. Obtained results showed that sugar fraction in molasses may vary, and different sugars are rapidly fermented by rumen microbes. Modern rationing models should consider a modification of sugar rates of digestion, since the actual one appears too slow than those observed in vitro.

• Highlights

• Molasses are unique blends of several sugars

• Major sugars are digested in few hours

• Rationing software should consider a faster rate of digestion for different sugars

摘要

甜菜和甘蔗糖蜜主要含有单糖和三糖，由己糖和微量的戊糖组成。但是，配给软件将糖仅作为一种实体，消化率约为20％h ^-1。这项初步研究的目的是研究和评估糖蜜中糖分的体外消化动力学和速率。从世界各地收集的各种样品中随机选择三种甜菜和三种甘蔗糖蜜，并在1、2、3、4、6、8和24小时通过体外瘤胃发酵进行消化。然后使用特定的酶试剂盒分析样品，以定量残留的蔗糖，葡萄糖，果糖，棉子糖，半乳糖和阿拉伯糖。在孵育的3小时内，蔗糖完全消失。葡萄糖和果糖在4-6小时内被完全消化，显示出样品之间的差异。即使不那么具有代表性，半乳糖也显示出相似的消化趋势（3-4小时内消化率为97％）。甘蔗糖蜜中的棉子糖相当慢，而甜菜糖蜜中的棉子糖则在1小时内被完全消化。阿拉伯糖 一种戊糖，从未完全消化，与其他糖相比，其发酵动力学有所不同。蔗糖，葡萄糖和果糖（糖蜜中最具代表性的糖）的消化率计算值高于50％h甘蔗和甜菜都为^-1。获得的结果表明，糖蜜中的糖分可能有所不同，不同的糖会被瘤胃微生物快速发酵。现代的配给模型应考虑修改糖的消化率，因为实际的消化率似乎比体外观察到的慢。

• 强调

• 糖蜜是几种糖的独特混合物

• 主要糖分在数小时内被消化

• 配给软件应考虑不同糖类的更快消化速率