Dept of Food Science and Technology, Oregon State Univ, Corvallis, OR 97331, USA.
J Food Sci. 2012 Feb;77(2):E45-51. doi: 10.1111/j.1750-3841.2011.02525.x. Epub 2012 Jan 12.
Sugar infusion is a widely used osmotic treatment for fruit preservation, but the process is inherently slow and the waxy skins of some fruits hinder mass transfer during the process. This work examined the utility of perforation by a carbon dioxide (CO(2)) laser as a novel skin treatment to improve the infusion process. In 2 experiments, individually quick frozen (IQF) blueberries were subjected to varying degrees of laser perforation (3 levels of perforation density × 3 levels of perforation depth), and then infused stepwise with high fructose corn syrup (HFCS) to a final °Brix of 70 using varying solution concentration increment (5, 10, 20, and 30 °Brix/d). At each concentration, increasing perforation density and depth promoted solute migration into the fruit with increased fruit weight (P < 0.05; up to 24.15%, 37.23%, 52.89%, 65.34% wt. increase at 5, 10, 20, and 30 °Brix/d compared to the controls). Laser-treated blueberries maintained the original shape without excessive shrinkage and texture hardening due to enhanced solute incorporation, while the controls and mechanically treated samples were ruptured and wrinkled at the end of the process. Increasing solution concentrations shortened the process duration but decreased final fruit weight due to greater osmotic gradients. However, negative effects of using higher solution concentrations on final fruit weight were significantly alleviated with moderate-to-high doses of laser perforation (P < 0.001). Overall, the results demonstrate that laser perforation can be a viable skin pretreatment technique, offering marked improvement on final process yield, process efficiency, and product quality.
CO(2) laser perforation as a novel skin pretreatment for sugar infusion of individually quick frozen (IQF) blueberries is presented. The technique markedly improves the product yield and quality. Although further investigation is needed, the method may potentially be used for other waxy skin fruits such as cranberries and cherries.
糖浸是一种广泛用于水果保鲜的渗透处理方法，但该过程本质上较慢，并且一些水果的蜡质表皮会在该过程中阻碍传质。这项工作研究了二氧化碳（CO 2 ）激光穿孔作为一种新颖的表皮处理方法来改善渗透过程的实用性。在 2 项实验中，对个体速冻（IQF）蓝莓进行不同程度的激光穿孔（穿孔密度 3 个水平×穿孔深度 3 个水平），然后用高果糖玉米糖浆（HFCS）分阶段逐级注入，最终达到 70°Brix 的浓度，使用不同的溶液浓度增量（5、10、20 和 30°Brix/d）。在每个浓度下，增加穿孔密度和深度都会促进溶质向水果中的迁移，从而增加水果的重量（P < 0.05；与对照相比，在 5、10、20 和 30°Brix/d 时，重量分别增加了 24.15%、37.23%、52.89%和 65.34%wt.）。激光处理的蓝莓保持了原始形状，没有因溶质掺入而过度收缩和质地变硬，而对照和机械处理的样品在处理结束时破裂和起皱。增加溶液浓度会缩短处理时间，但由于渗透压梯度较大，最终会降低水果的重量。然而，使用较高溶液浓度对最终水果重量的负面影响在使用中等到高剂量激光穿孔时会显著减轻（P < 0.001）。总的来说，结果表明，激光穿孔可以作为一种可行的表皮预处理技术，在最终的加工收率、加工效率和产品质量方面提供显著的改善。
CO 2 激光穿孔作为一种新颖的个体速冻（IQF）蓝莓糖浸用表皮预处理方法。该技术显著提高了产品的产量和质量。虽然需要进一步研究，但该方法可能可用于其他蜡质表皮的水果，如蔓越莓和樱桃。
