Influence of Adding Certain Aromatic Herbs on Technological Properties of Acidophilus- Bifidus-Thermophilus (ABT) Cultured Milk

摘要

Ever-Growing consumer demand for convenience, combined with a healthy diet and preference for natural ingredients has led to a growth in functional food markets. Current trends and changing consumer needs indicate a great opportunity for innovations and developments in fermented milks. Scientific and clinical evidence is also mounting to corroborate the consumer perception of health from fermented milks. Healthy aromatic herbs and associated ingredients (essential oils) add an attractive dimension to cultured dairy products, and another potential growth area for fermented milks includes physiologically active anti-microbial, antioxidant and pleasant flavours. Furthermore, they are used as bio-preservatives. Herbal ABT cultured milk was manufactured, by inoculating (L. acidophilus, Bifido lactis and S. thermophilus in ratio 1:1:1 v/v) in heat treated buffalo' milk, contained 0.25% chamomile, marjoram, ginger or rosemary powder. Chemical, microbiological and organoleptic properties were determined at intervals during 15 days of storage at 6±1℃. The results illustrated that: L acidophilus viable counts were the highest (P≤0.001) counts with marjoram ABT fresh milk, while rosemary and chamomile ABT milk recorded the highest counts at the end of refrigerated storage. The counts of Bifido lactis with marjoram and chamomile ABT milk were highly significant (P≤0.001) compared with other treatments. Viability of B. lactis and L acidophilus in ABT milk remained above 106 cfu/ml in all treatments until the end of the storage period. The coliform group, Staphylococcus aureus, yeasts and molds were not detected in all treatments whether fresh or during cold storage. Acidity (TA) was developed in all treatments during storage; particularly with chamomile ABT milk which contained the highest value (P≤0.001) TA and the lowest (P≤0.001) pH values and lactose content. Rosemary ABT milk gave the highest acetaldehyde content (285ppm) on fresh, while chamomile ABT milk had it at the end of cold storage period. Marjoram ABT milk had the highest significant (P≤0.001) diacetyl content and WSN/TN on fresh. Concerning the organoleptic properties, scores decreased significantly (P≤0.001) during the storage period, although all treatments were still acceptable until the end of the storage period. The highest significant total scoring was obtained with rosemary, ginger and control ABT milk treatments.