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LWT - Food Science and Technology
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Sensory characteristics of commercial lactose-free milks manufactured in the United States
Koushik Adhikari*, Lauren M. Dooley, Edgar Chambers IV, Natnicha Bhumiratana
Sensory Analysis Center, Kansas StateUniversity, Manhattan, KS 66506, USA
a r t i c l e i n f o
Article history: Received 17 September 2008 Received in revised form 22 June 2009 Accepted 23 June 2009 Keywords: Ultrapasteurized lactose-free milk Descriptive analysis Consumer acceptability PLS regression
a b s t r a c t
This study determined the sensory characteristics of ultrapasteurized (UP) lactose-free milk of different fatcontents, and compared them with regular milk. Nine milk samples (six UP lactose-free and three regular) containing 0, 2 or 3 g milkfat/100 mL were tested by a descriptive panel. A consumer test with three UP lactose-free milk and three regular samples was also conducted. The skim milks were found to be lacking in freshness and the dairy notes were lower compared to the higher-fat-content milks. The UPlactose-free milks were different from the regular milk because of higher intensities of cooked, processed, and sweet attributes. UP lactose-free milks tended to score higher than the regular milks at the same fat content for dairy-related attributes, but this difference was not signiﬁcant for the reduced-fat milks. Although majority of the consumers in the present study were aware that UPlactose-free milks existed in the market, only few had tasted them before. The higher intensities of cooked and sweet ﬂavor attributes in the UP lactose-free milks might be a hindrance to their consumption by the lactose-intolerant population. More efforts are needed from the dairy industry to develop better lactose-free products and to educate consumers about lactose-free dairy products. Ó 2009 ElsevierLtd. All rights reserved.
1. Introduction Between 30 and 50 million consumers in the U.S. (approximately 25% of the U.S. adult population) and more than 70% of the world’s population are lactose-intolerant, which varies by race and age (Messia, Candigliota, & Marconi, 2007). Lactose-intolerance occurs when the human body is unable to produce the lactase enzyme required to break down lactose toglucose and galactose for the body to metabolize. As a result, the lactose is fermented in the intestine where it can produce unpleasant conditions such as gas, bloating, and diarrhea. Commercial lactose-free milk contains less than 0.25 g lactose per 100 g of milk and is manufactured via enzymatic hydrolysis by breaking down the lactose in milk to glucose and galactose. Lactose usually ispresent in milk at levels of 4–6 g/100 mL. Glucose and galactose resulting from hydrolysis of lactose are sweeter than lactose, and thereby can increase the sweetness of the lactose-free milks. The demand for lactose-free dairy products has increased by approximately 20% per year since 1997 in the U.S. (Jelen & Tossavainen, 2003). Generic brands of lactose-free milk also are making their way into themarket. While lactose-free milks have addressed the needs of lactoseintolerant consumers, there still needs to be a strong similarity to
* Corresponding author. E-mail address: firstname.lastname@example.org (K. Adhikari). 0023-6438/$ – see front matter Ó 2009 Elsevier Ltd. All rights reserved. doi:10.1016/j.lwt.2009.06.017
regular milk for the consumer to purchase the product and be satisﬁed. Dairyproduct acceptance is primarily sensory-driven (Claasen & Lawless, 1992). Milk ﬂavor can be affected by many variables, including chemical reactions and microbial growth (Francis et al., 2005). However, not only is ﬂavor an important component of the milk sensory experience, so too are texture and appearance. Flavor has a direct relationship to consumer acceptance, and is the most important factor for...