食品伙伴網(wǎng)報道，美國營養(yǎng)成分網(wǎng)消息介紹了食品科技動態(tài)雜志（Trends in Food Science & Technology）所發(fā)布的一項最新研究成果。來自巴西的研究者提出，對益生菌乳制品采取新興的具有前景良好的兩種加工技術(shù)（高壓加工法(HP)和電場脈沖法（PEF)）可以確保乳制品中益生菌的生存，以及乳制品的保質(zhì)期。
傳統(tǒng)的加熱技術(shù)會破壞有益的菌群，該項研究探討了新技術(shù)是否會對益生菌的傷害減少,并且談及若推廣應(yīng)用這兩項技術(shù)，則極有可能擴大益生菌市場的空間。除了克服了加熱會造成破壞這個問題，這兩種加工方法還各有特色，可能對一些質(zhì)量參數(shù)產(chǎn)生積極的影響，比如說HP加工法可以改善口感、而PEF加工法則在奶酪加工中表現(xiàn)出色，可改進牛乳的凝結(jié)度、凝結(jié)時間等等因素。
但是這兩項工藝也存在劣勢，首先，雖然近年HP加工設(shè)備的價格有所下調(diào)，但仍很昂貴；而PEF技術(shù)則會降低益生菌對酸和膽汁的耐受性，可能會損害益生菌的效果。并且，除了上述的技術(shù)問題之外，還有消費者能否接受的問題，作者提到，似乎消費者更傾向于接受HP加工法。
食品伙伴網(wǎng)編者注：對文中兩種加工工藝是按照字面意思直譯，缺乏專業(yè)涵義，與實際應(yīng)用有出入，請參照英文原文。
本報道由食品伙伴網(wǎng)編譯整理，僅供食品行業(yè)相關(guān)人士參考，詳細內(nèi)容以國外原文報道為準。
原文報道：
New processing technologies could enhance probiotic dairy products
By Guy Montague-Jones, 06-Aug-2010
An academic review has underlined the promise of high pressure processing (HP) and pulsed electric fields (PEF) to ensure the viability and shelf life of probiotic dairy products.
Writing in the journal Trends in Food Science & Technology, Brazilian scientists said the two emerging processing technologies could help maintain the functional properties of probiotics.
Because traditional thermal techniques can destroy the friendly bacteria, studies have been conducted to see if new technologies could do a better job. This work could potentially expand the food shelf space currently open to probiotics.
Promising technologies
Reviewing the literature relevant to processing probiotic milk products, the Brazilian scientists said: “The application of HP and PEF to develop dairy foods supplemented with probiotic cultures is promising.”
In addition to overcoming the problem of heat related damage, the scientists said these emerging technologies may have a positive impact on some quality parameters. For example, in probiotic yoghurts the scientists note that HP treatment may improve the texture, delivering firmer and thicker products.
And pulsed electric field techniques have been advanced as having significant potential for cheese manufacturing because studies have reported improvements in the coagulation properties of the milk, such as gel firmness and time of coagulation during cheese production.
Potential drawbacks
But drawbacks do remain to both these technologies. For example, equipment for high pressure processing remains expensive despite cost reductions over recent years.
In addition, some concerns remain about product quality. For example, the authors reference research that suggests PEF treatment may reduce tolerance to acid and bile in probiotic dairy products, potentially compromising their probiotic potential.
