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The occurrence of L(+)-lactate crystals in hard cheeses continues to be an expense to the cheese industry. Salt tolerance of the starter culture and the salt-to-moisture ratio (S:M) in cheese dictate the final pH of cheese, which influences calcium lactate crystal (CLC) formation. This research investigates these interactions on the occurrence of CLC. A commercial starter was selected based on its sensitivity to salt, less than and greater than 4.0% S:M. Cheddar cheese was made by using either whole milk (3.25% protein, 3.85% fat) or whole milk supplemented with cream and ultrafiltered milk (4.50% protein, 5.30% fat). Calculated amounts of salt were added at milling (pH 5.40 +/- 0.02) to obtain cheeses with less than 3.6% and greater than 4.5% S:M. Total and soluble calcium, total lactic acid, and pH were measured and the development of CLC was monitored in cheeses. All cheeses were vacuum packaged and gas flushed with nitrogen gas and aged at 7.2 degrees C for 15 wk. Concentration of total lactic acid in high S:M cheeses ranged from 0.73 to 0.80 g/100 g of cheese, whereas that in low S:M cheeses ranged from 1.86 to 1.97 g/100 g of cheese at the end of 15 wk of aging because of the salt sensitivity of the starter culture. Concentrated milk cheeses with low and high S:M exhibited a 30 to 28% increase in total calcium (1,242 and 1,239 mg/100 g of cheese, respectively) compared with whole milk cheeses with low and high S:M (954 and 967 mg/100 g of cheese, respectively) throughout aging. Soluble calcium was 41 to 35% greater in low S:M cheeses (low-salt whole milk cheese and low-salt concentrated milk cheese; 496 and 524 mg/100 g of cheese, respectively) compared with high S:M cheeses (high-salt whole milk cheese and high-salt concentrated milk cheese; 351 and 387 mg/100 g of cheese, respectively). Because of the lower pH of the low S:M cheeses, CLC were observed in low S:M cheeses. However, the greatest intensity of CLC was observed in gas-flushed cheeses made with milk containing increased protein concentration because of the increased content of calcium available for CLC formation. These results show that the occurrence of CLC is dependent on cheese milk concentration and pH of the cheese, which can be influenced by S:M and cheese microflora.

The occurrence of calcium lactate crystals (CLC) in hard cheeses is a continual expense to the cheese industry, as consumers fail to purchase cheeses with this quality defect. This research investigates the effects of the protein concentration of cheese milk and the pH of cheese on the occurrence of CLC. Atomic absorption spectroscopy was used to determine total and soluble calcium concentrations in skim milk (SM1, 8.7% total solids), and skim milk supplemented with nonfat dry milk (CSM1, 13.5% total solids). Calcium, phosphorus, lactic acid, and citrate were determined in cheeses made with skim milk (SM2, 3.14% protein), skim milk supplemented with ultrafiltered milk (CSM2, 6.80% protein), and nonfat dry milk (CSM3, 6.80% protein). Supplementation with nonfat dry milk increased the initial total calcium in CSM1 (210 mg/100 g of milk) by 52% compared with the total calcium in SM1 (138 mg/100 g of milk). At pH 5.4, soluble calcium concentrations in CSM1 were 68% greater than soluble calcium in SM1. In cheeses made from CSM2 and CSM3, total calcium was 26% greater than in cheeses made from SM2. As the pH of cheeses made from SM2 decreased from 5.4 to 5.1, the concentration of soluble calcium increased by 61.6%. In cheeses made from CSM2 and CSM3, the concentrations of soluble calcium increased by 41.4 and 45.5%, respectively. Calcium lactate crystals were observed in cheeses made from SM2 at and below pH 5.1, whereas CLC were observed in cheeses from CSM2 and CSM3 at and below pH 5.3. The increased presence of soluble calcium can potentially cause CLC to occur in cheese manufactured with increased concentrations of milk solids, particularly at and below pH 5.1.

A sanitized cheese plant was swabbed for the presence of nonstarter lactic acid bacteria (NSLAB) biofilms. Swabs were analyzed to determine the sources and microorganisms responsible for contamination. In pilot plant experiments, cheese vats filled with standard cheese milk (lactose:protein = 1.47) and ultrafiltered cheese milk (lactose:protein = 1.23) were inoculated with Lactococcus lactis ssp. cremoris starter culture (8 log cfu/mL) with or without Lactobacillus curvatus or Pediococci acidilactici as adjunct cultures (2 log cfu/mL). Cheddar cheeses were aged at 7.2 or 10 degrees C for 168 d. The raw milk silo, ultrafiltration unit, cheddaring belt, and cheese tower had NSLAB biofilms ranging from 2 to 4 log cfu/100 cm2. The population of Lb. curvatus reached 8 log cfu/g, whereas P. acidilactici reached 7 log cfu/g of experimental Cheddar cheese in 14 d. Higher NSLAB counts were observed in the first 14 d of aging in cheese stored at 10 degrees C compared with that stored at 7.2 degrees C. However, microbial counts decreased more quickly in Cheddar cheeses aged at 10 degrees C compared with 7.2 degrees C after 28 d. In cheeses without specific adjunct cultures (Lb. curvatus or P. acidilactici), calcium lactate crystals were not observed within 168 d. However, crystals were observed after only 56 d in cheeses containing Lb. curvatus, which also had increased concentration of D(-)-lactic acid compared with control cheeses. Our research shows that low levels of contamination with certain NSLAB can result in calcium lactate crystals, regardless of lactose:protein ratio.

The article examines low-fat cheddar cheese for fat mimetics. It describes cheese with 60% reduced fat content that were processed with three commercial fat mimetics and aged for 3 months before sensory and instrumental evaluation. Results show that low-fat cheese that had one fat mimetics got the highest texture scores while the low-fat control got higher flavor score. Low-fat cheeses containing fat mimetics were not rubbery compared to low-fat control cheese.

Calcium lactate crystals (CLC) in hard cheeses continue to be an expense to the cheese industry. Major causes of L(+) lactate crystals appears to be 1) increasing protein concentration in cheese milk, which increases cheese yield and 2) type of packaging, which influences serum calcium migration. The research investigates the effects of protein concentration and packaging on migration of serum calcium to the surface of cheese during storage and CLC occurrence. Total and soluble calcium, phosphorus, lactic acid and citrate were measured in cheeses made with skim milk (SM1, 3.14% protein) and skim milk supplemented with ultrafiltered milk (UF) (CSM1, 6.80% protein) or NFDM (CSM2, 6.80% protein). Vacuum and gas flushed cheeses were analyzed for total and soluble calcium, lactic acid and salt at four specific distances from the center of cheeses made from whole milk (WM1) and whole milk supplemented with UF (CWM1). Cheeses made from CSM1 and CSM2, had 26% higher total calcium (1367 mg/100g and 1375 mg/100g cheese, respectively), than cheeses made from SM1 (1066 mg/100g of cheese). At pH 5.2, soluble calcium in cheeses made from CSM1 and CSM2, (550 mg/100g and 558 mg/100g cheese, respectively) was 25% higher than cheeses made from SM1 (441 mg/100g of cheese). At week 10, higher (8%) total and soluble calcium were observed on surfaces of cheeses made from WM1 that were gas flushed compared to the center of the cheese blocks. In contrast, hardly any change was observed in vacuum packaged cheeses, showing that migration of serum calcium to the surface of cheeses was more prevalent in gas flushed cheeses. These results confirm that the risk of occurrence of CLC in cheese increases with concentration of milk proteins. Additionally, loose packaging enhances serum calcium migration to cheese surfaces, increasing the concentration of calcium ions and the risk of CLC. [ABSTRACT FROM AUTHOR]