Production of farmstead lactose-free Pecorino di Osilo and ricotta cheeses from sheep’s milk

Abstract

The present work was aimed to define and validate farmstead production of lactose-free Pecorino di Osilo cheese, fresh ricotta cheese, and salted and smoked ricotta cheese (Ricotta mustia). The enzymatic activity of the commercial preparation containing lactase (1.1 g/mL), preliminarily tested using a spectrophotometric titration, showed activity equal to 4950±40 neutral lactase unit/g. The amount of lactase required to obtain the lactose-free milk was then established in triplicate laboratory trials, by adding the enzyme at concentrations of 0.7, 0.9 and 1.1 g/L in flasks containing 160 mL of raw sheep’s milk. Samples were incubated under conditions expected during milk storage and cheese-making. The residual lactose content in milk was determined by enzymatic method. The addition of lactase at concentration of 1.1 g/L of milk reduced the lactose concentration below the limit of detection (LOD) of 0.06 g/L. The procedure was validated at a dairy farm, using three different batches of bulk raw sheep’s lactose-free milk that were transformed into Pecorino di Osilo cheese. The resulting whey was used to produce fresh ricotta and Ricotta mustia cheese. Raw milk and whey samples were always below lactose detection limit. The residual lactose was measured in Pecorino di Osilo cheese, after 24 hours and 30 days from production; in fresh ricotta cheese, after 48 hours; in Ricotta mustia cheese after 7 days. The determination of lactose content in cheese samples was conducted by a gas chromatography-flame ionization detection method, which showed a LOD and limit of quantification respectively of 1.8 and 5.6 mg/kg for cheese, and 1.35 and 4.2 mg/kg for both ricotta cheeses. The lactose concentration was always below the relevant LOD values in all samples. The mean concentration of galactose and glucose were respectively 13,000±2000 and 11,000±2000 mg/kg in fresh Pecorino di Osilo, 1100±300 and 1200±300 mg/kg in fresh ricotta, and 950±400 and 750±250 mg/kg in Ricotta mustia. The results of the present study showed that the production of farmstead lactose-free Pecorino di Osilo cheese and ricotta cheeses from raw sheep’s milk is easily achievable. The main issue for farmstead production of artisanal lactose-free products is the implementation of permanent procedures based on hazard-analysis and critical control principles aimed at guaranteeing the effectiveness of the process and at acquiring analytical evidences to demonstrate the fulfilment of law requirements for labelling.

Biogenic Amines in Traditional Fiore Sardo PDO Sheep Cheese: Assessment, Validation and Application of an RP-HPLC-DAD-UV Method

“…While one contribution has been published containing data on the amounts of BAs in other sheep's cheeses from Sardinia [71], unfortunately the validation part of the analytical method is missing. For this reason, and on the basis of the previous results that our research group has achieved in last years in the assessment, validation and application of new methods for the determination of analytes of specific interest in sheep cheeses [65,67,[72][73][74], the principal aim of this study is to develop and validate an original RP-HPLC method devoted to the determination of eight BAs (i.e., Tyr, Trp, His, Put, Cad, Phe, Spm, Spd, all reported in Figure 1) in Fiore Sardo sheep's cheese. determination of eight BAs (i.e., Tyr, Trp, His, Put, Cad, Phe, Spm, Spd, all reported in Figure 1) in Fiore Sardo sheep's cheese.…”

Characterization and Quantification of Proteins in Whey Obtained as a by-Product From White Cheese and Yellow Cheese Production

“…Knowledge of whey composition and adjustments of the process parameters in whey cheese technology could allow manufacturing of whey cheese to realize maximal yield. Also, white cheese whey could be the basic raw material for the production of traditional lactose free whey cheese [10,11]. Usage of waste whey in some products will contribute in improvement of physicochemical parameters (COD, BOD, pH) of waste water and environmental protection [12].…”

Active and Intelligent Packaging of Cheese: Developments and Future Scope

“…An innovative ethylene-vinyl alcohol copolymer (EVOH) plastic encompassing 30% beta-cyclodextrins reduced the cholesterol concentration by 23% in UHT milk [100]. Such type of active plastic films could be incorporated with β-galactosidase enzyme (lactase) and explored for the development of lactose free whey cheeses due to increased incidences of lactose intolerance across the globe [101].…”